Can Anyone Tell Me Which???

[HollowPoint]

I have another DIY project in the planning stage and I've been trying to gather as much information on the subject as I can before starting my prototyping experiments.

I need to know the correct type of resin to use in order to Carbon Fiber Wrap a couple of the left over take-off rifle barrels I have in my storage closet. I want to use those two take-off barrels as Guinea Pigs before ruining a perfectly good barrel that I can actually use.

I have reached out to some of the manufactures of these outrageously expensive barrels to ask the exact type of resin they use and where I might get my hands on some but there are only a handful of these Carbon Fiber barrel wrapping businesses and since they have the market for such things pretty much to themselves I get the distinct sense that they are reluctant to share such information with a home gunsmithing do-it-yourselfer like me or you. Imagine if the gunsmiths learned that although it may have taken engineers and rocket scientist to initially figure it all out -having figured out the Carbon Fiber wrapping process- it turns out that it really isn't that hard to do. Keeping everyone in the dark about it essentially would mean keeping profit margins high for the handful of manufactures. Incidentally, it took engineers and even some Rocket Scientists to figure out how to advance modern firearms and now here we are with home gunsmiths and actual gunsmiths doing the same thing. This leads me to believe that the same is most likely true of Carbon Fiber wrapping a barrel.

For the most part, the information available on the internet has to do mainly with marketing hype from the few manufactures that make and sell these barrels. Little is mentioned about the actual name, type or sources of the resin they use. I can get the correct type of Carbon Fiber from alot of sources; even on Ebay. I can even rig up a winding jig with my metal lathe but, it's the bonding agent that I'm looking for.

Can any of you guys out there in Cast Boolits Land shed any light on this for me? I've read as much as I can on the subject from the actual experts and, far to much from the self-proclaimed internet "Experts." I'm finding that like with my Swiss K31 re-barreling project, when I went looking for information in the forums and chat rooms where I thought that info could be found, the Na-Sayers were falling all over themselves for the chance to tell me all the reasons that their self-assigned "Expertise" dictated that such a project should be left to the experts alone. I don't recall any such dream-killing replies here on the Cast Boolits forum. When I did post that K31 project all I got was alot of interest in the subject so, here I am again posting this DIY Carbon Fiber Barrel wrapping project. If you have any helpful information you can share about the correct type of resin to bond the Carbon Fiber to the barrel and to itself, I'd appreciate it.

If I had listened to those self-appointed "Experts" I wouldn't have become one of the few DIY people on the planet who had successfully rebarreled a K31 Swiss rifle and re-chambered it in the 6.5x55 Swedish cartridge. I'd like to be among the first who has successfully and safely Carbon Fiber Wrapped his own rifle barrels too. I just need to find out the exact type of resin to use and where to get it.

HollowPoint

[Remiel]

I got out of racing when carbon fiber was just be coming commonplace, I would check with performance company's and ask what they use for their high heat applications. It could be similar or the same, I have been surprised in how much certain technologies overlap in the most uncommon of places.

Sent from my SM-G920V using Tapatalk

[HollowPoint]

I got out of racing when carbon fiber was just be coming commonplace, I would check with performance company's and ask what they use for their high heat applications. It could be similar or the same, I have been surprised in how much certain technologies overlap in the most uncommon of places.

Sent from my SM-G920V using Tapatalk

You could be right. I never thought of that. If they do overlap somehow there's a better chance of getting that resin information from those who may not feel as threatened by sharing that info with a DIY guy and his home gunsmithing project. Thanks for your reply.

HollowPoint

[cwtebay]

I don't know if it's the same thing, but Max HTE has served quite well on some carbon fiber wrapping that I do on a fairly regular basis. But as the above posters say - ask some experts!

Sent from my Pixel 3 XL using Tapatalk

[HollowPoint]

I don't know if it's the same thing, but Max HTE has served quite well on some carbon fiber wrapping that I do on a fairly regular basis. But as the above posters say - ask some experts!

Sent from my Pixel 3 XL using Tapatalk

I'm still searching. I am now going through some YouTube videos that I missed before and leaving inquiries there as well. Thanks for your reply. I asked my questions here because it's a gun related sight and I figured that among the huge number of members here there is bound to be one or two guys who have some hands on experience or knowledge of Carbon Fiber wrapping gun barrels; either through their work or their friends or relatives connections.

HollowPoint

[ulav8r]

Some experimental aircraft use carbon fiber. You should be able to find information on that use.

[dtknowles]

Where I work we use IM7/977-3 tow preg to make a high performing Aerospace product

[HollowPoint]

Thanks to all you guy who have taken the time to reply. I'm still looking for the right stuff. I did inquire of some of the trades you all have referred to. Those who have actually answered my inquiries have all stated basically the same thing but with different words.

These different trades such as those using some form of Carbon Fiber laminating, bonding and forming did basically what I'm doing now. They went in search of this information they needed until they found it. The resins or bonding agents they're using are those needed for their specific applications, be it forming Carbon Fiber parts from Aerospace to bicycles. For the most part, they too had to rely the expertise of others to tell them which resin or bonding agent was best for their application. That's where I'm at right now. Asking for this information directly from the Carbon Fiber Wrapped barrel manufactures is like pulling teeth without any anesthetic. I've come to the conclusion that what I really need is to ask the actual experts who formulate these resins, not necessarily from those who know how to apply the resins but have no knowledge of how they work.

So now I'm just doing internet searches for the makers/manufactures and sellers of Carbon Fiber bonding agents or resins. Here too, I've run into problems because these manufactures are reluctant to deal with an individual DIY-Dreamer like myself or yourself. They are wanting to attract larger orders for their products rather than a pint or gallon sale here or there. I have yet to receive any replies from any of the manufactures of these resins but in all fairness, my inquiry emails were sent early on a weekend close to the Christmas holiday. I might get a reply next week or after Christmas when everyone is back to work or maybe never; who knows. In the mean time I'll just keep looking.

I did come across a couple of candidate resins that might be the correct type of resin to use by looking up the Max HTE resin that cwtebay mentioned in his reply. Although the specs on that resin didn't really show the ability to withstand the type of effects it would be subjected to on a fired rifle barrel, it did lead me to some other resin formulations that did appear to have these qualities. I'd like to get the right stuff the first time out to minimize the trial and error that my DIY projects are prone to having.

That's where I'm at right now. If any of you happen to come across someone with knowledge on the subject maybe you can pick their brain for me and share with us what they have to say on the subject. I'll be back.

HollowPoint

[JimB..]

Maybe I’m clueless, but I would have guessed that the barrel companies install a barrel inside a piece of tube that they buy. They focus on the endcaps and barrel. Anyone know otherwise?

[Winger Ed.]

Check out 'US Composites'. They have all that stuff.

Not their carbon fiber things, but I've bought from them before and they were good to deal with.

[HollowPoint]

Maybe I’m clueless, but I would have guessed that the barrel companies install a barrel inside a piece of tube that they buy. They focus on the endcaps and barrel. Anyone know otherwise?

You are not clueless. There are a handful of manufactures that do this Carbon Fiber barrel wrapping process. One of them (I think it's BSF) uses a process similar to what you've described. In my search for more information on the various wrapping processes that these outfits use I believe that most of them simply turn down existing barrel blanks and replace the removed metal with Carbon Fiber. This one producer of Carbon Fiber wrapped barrels does in fact just wrap a mandrel of the appropriate diameter and when cured, they slip it into place onto their turned down and threaded barrels then secure it in place with threaded end caps. If I'm not mistaken most of their barrels are shorter and made for AR 15 platform guns. They are turned down in segments of staggered diameters from larger to smaller so that they can slip the Carbon Fiber tubes into place, secure them, then slip another tube into place then secure that with a threaded muzzle cap and so on.

I actually started some CAD models of possible methods of going about the wrapping procedure. What I mean is; I've modeled the profiles of three different turned-down barrels. Two would be wrapped without the threaded end caps to sandwich the Carbon Fiber tubes in place and one of those CAD models is of a shorter barrel modeled in such a manner that I'd simply be winding or wrapping the Carbon Fiber onto a mandrel of a matching diameter then after curing, removing it from the mandrel and slipping it into place onto my turned down barrel; then securing it with those threaded end caps. I did this just so I could visualize it a bit better before actually trying it. I may post those CAD models later but I don't want to get ahead of myself. After seeing them maybe you all could tell me what your gut-feeling tells you about these possible ways of going about the actual areas to be wrapped.

It's incredibly simple to Over-Complicate the entire process by Over-Thinking it AND just as easy to Over- Simplify it too. In my mind's eye, I just don't see it as being that complicated. The only thing holding me up right now is finding the correct resin for this application.

Initially I thought that the first few wraps, which included those parts of the Carbon Fiber filament that make contact with the barrel metal, had to be bonded to the actual metal of the barrel but, what I'm seeing now from having taken a closer look at the winding or wrapping process that the BSF Carbon Fiber barrel maker uses, the actual Carbon Fiber tube isn't bonded to the barrel. It's sandwiched in place by the pressure of the threaded end caps. Whether the Carbon Fiber filaments are bonded to the metal of those Carbon Fiber barrels that are wrapped from end to end -without the threaded end caps- is yet to be determined. I'm still in the learning stage of this DIY project. I already know more than I did when I started but that still isn't quite good enough for me to dive right in at this point.

HollowPoint

[samari46]

This may not be what you are looking for so here goes. Think it was on the show "How It's Made". They were carbon fiber wrapping an entire body of a jet and they did mention that the carbon fiber tape they were using was already impregnated with the resin and hardener. they were putting on the carbon fiber in about two inch strips from what looked like a huge roll of carbon fiber. Naturally there was some kind of tensioning device and a roller to apply the tape. I'm thinking that you would be using a stranded type of carbon fiber. Only problem is that the resin and hardner would have to have a long pot life (from the time you mix it until it starts to set up) much like bedding compound. You may want to check with Devcon or Belzona who do mfg different plastic metals some with high temp applications. Frank

[Wheelguns 1961]

I imagine it is some form of epoxy. Try reaching out to west system epoxy. I used to build boats, and west system was a leader in the epoxy field. They have always been very free with technical information. Explain to them that you need a high temp formula, and see what they say.

[akajun]

I have toured a carbon fiber barrel plant as I know the owner and can tell you that there is a lot of work put into them and they earn the dollars that they cost. I can also tell you that the cf material and epoxy is not as important as the wrapping process, the, curing, then the finishing/ machining of the cf. BTW its a dirty nasty process that eats up tooling/machines. No way in hell I'd mess with it without the proper ppe, downdraft, ventilation, and hell even another building as that dust gets everywhere.
Not going anywhere near my lathe with it either.

[HollowPoint]

Samari46: I think I may have viewed either the video you're referring to or a similar video. It shows basically what I've pictured in my mind regarding the process of wrapping Carbon Fiber, except that the strips of filament I'd be dealing with are no where near as wide.

Wheelguns1961: At this point I'm still not really sure if it's technically an epoxy, a resin or some other type of bonding agent. What I am sure of is that it has to be able to withstand high temperatures. I have come across some resins made for wrapping various types of materials including Carbon Fiber, Fiber Glass and some others I can't remember the name of right now. My road block now is that I want to make sure I'm buying the right stuff; the optimum stuff before plopping down my nickels and dimes.

akajun: I have taken all of that into consideration. That doesn't mean that I've got it all covered. It just means that I know what I'm up against.

Thanks for your input guys. I really do appreciate it. I'm still doing my research, waiting for replies to emails I've sent and doing my due diligence.

HollowPoint

[RoyEllis]

Try giving RAKA Inc. a call, they've been quite helpful on some of my CF projects. 772-489-4070 but I think they're closed til after New Years day.

[HollowPoint]

Try giving RAKA Inc. a call, they've been quite helpful on some of my CF projects. 772-489-4070 but I think they're closed til after New Years day.

Thanks Roy Ellis: I'll write that number down and give it a try if I don't get any replies to any of the email inquiries I've sent out.

HollowPoint

[HollowPoint]

I finally got a reply to one of my email inquiries to those producers, manufactures, vendors of resins. I got the contact information from off of the X-Winder website.

For those of you who aren't familiar with X-Winder, neither was I until I decided to learn how to Carbon Fiber wrap my own barrels. Soller Composites, LLC; the guy who replied to my email was Jon Soller. This is the closest I've come so far to getting some specific answers to my questions. I asked two specific questions in my email; which Carbon Fiber/Tow and which Resin.

With the limited information I supplied him in my email (I'd be wrapping Stainless Steel gun barrels that would be subjected to high heat) he replied with a couple of specific recommendations. Rather than paraphrasing I've just cut and pasted our email correspondence thus far. I'll contact him again after the holiday because I have two or three more questions I need clarification on.

HollowPoint



Greetings from Arizona:

I got your contact information for the X-Winder website where I recently became a member. I will be buying one of their X-Winder units in the upcoming months but in the mean time I have been doing my due diligence in the form of research regarding Carbon Fiber materials and the bonding agents or resins used to bond this material together. There is so much general information out there that it’s easy to get beat down by Information -Overload. That’s where I’m at right now; beat down.

You appear to be held in high enough regard for the folks over at the X-Winder website to list Soller Composites as a trusted provider of both materials and expertise in the field of Carbon Fiber Wrapping.

To this end I thought I would take a chance and inquire directly from the experts in this field. It is my intent to wrap small diameter Stainless Steel rifle barrels with Carbon Fiber. In my search for specific information regarding this application I’ve come across a lot of marketing hype from the handful of those who have already arrived at the correct type of Carbon Fiber, the Correct type of bonding agent and winding processes to end up with a durable and heat resistant finished product.

Is there any specific information you can share with me to narrow down the choices in the type of Carbon Fiber and Resin for this particular application? If not, can you direct me to a specific information resource that will help me determine the correct components for my Carbon Fiber Wrapping foray? Incidentally, I’m a private gunsmith who has grown weary of paying up to eight-hundred-bucks a pop for Carbon Fiber Wrapped barrels that have been put together by one of the small handful of business that specialize in this area of gunsmith supplies. I think it’s time to make this technology available to all the other gunsmiths out there looking for some relief as well.

Thanks in advance for taking the time to reply.

Tim M.


Hi Tim,

We own an xwinder, we sell tow (carbon, aramid, fiberglass, etc), we sell sleeves (tubular fabrics), and flat fabrics.

We sell to this industry and there seems to be many different approaches. Some use flat fabrics, many use our carbon sleeves,
some do their own winding, and we sell them tow. Which approach you use depends on several factors (I'll assume you
settled on one of them, otherwise call me after the new year and we can discuss this).

If you want to go the winding route, which seems the way you are considering, it is the cheapest from a material perspective.
Most use a 12K tow and we are about to have a huge tow sale.

The epoxy should be easy. We sell, to the best of our knowledge, the highest temp 2 part epoxy in the world: Adtech 820.
It is good to over 215F which makes it ideal for gun barrels and works well in the xwinder resin bath.

There are other 2 part epoxies out there, but most of the goods ones start to soften between 160 & 180F (typically closer to
160F).

Being Xmas eve, I need to finish up and get home, but I hope this gets you started and is somewhat helpful. If you want
more help email (or call in Jan) and I'll be happy to help you out to the best of my ability.

Best Regards,

[HollowPoint]

I have a few different way I could go about this once I get all the components for this project together. I already have the donor barrels so I thought I'd do the stainless factory barrel I got when I re-barreled my 223 Tikka Lite.
,
Below is one of the CAD renderings I drew up just to help me visualize this project as I pictured it in my mind. It's not drawn to the exact size I had envisioned. It's just drawn to give myself and anyone who might ask what the heck I was dreaming about.

I think that for the first ever attempt this method may be the easiest. If any kind of heat curing is required, the two short lengths of Carbon Fiber tubing will fit nicely into my small curing oven. I'll post my other two computer renderings later.

HollowPoint

[JimB..]

I don’t know how you’re going to define success for this project, just wrapping a barrel or getting some clear benefit from doing so. If the latter, I dislike your design. The placement of that center nut and the differing tension on the front and back of the barrel are new variables in a game where fewer variables seems best. Heck I don’t even like the stepped profile since it’ll hold heat differently, but if that’s what folks are doing then my concerns are probably overblown.

Think hard about sleeving rather than wrapping. You probably have to turn a profile to match a sleeve that they already make, but that’s relatively easy. A tangential benefit is that in the shopping for a sleeve you’ll learn a lot about the barrel profiles that more experienced barrel makers have selected.

good luck, it’s always good to push the boundaries of what we can do ourselves.

[HollowPoint]

I don’t know how you’re going to define success for this project, just wrapping a barrel or getting some clear benefit from doing so. If the latter, I dislike your design. The placement of that center nut and the differing tension on the front and back of the barrel are new variables in a game where fewer variables seems best. Heck I don’t even like the stepped profile since it’ll hold heat differently, but if that’s what folks are doing then my concerns are probably overblown.

Think hard about sleeving rather than wrapping. You probably have to turn a profile to match a sleeve that they already make, but that’s relatively easy. A tangential benefit is that in the shopping for a sleeve you’ll learn a lot about the barrel profiles that more experienced barrel makers have selected.

good luck, it’s always good to push the boundaries of what we can do ourselves.


Judging from your comment I tend to think that you haven't read this thread from the beginning. Sounds like you may have jumped in near my last few posts. For me "Success" is defined in incremental steps. I want to succeed in actually being able to wrap my own Carbon Fiber barrels. This means starting with these short lengths of Carbon Fiber tubes then transferring them to my turned down barrels. This to me is doable by the average joe.

Like you've alluded to, turning down and threading the barrel and the matching mandrels is the easy part as far as I'm concerned. It's the traversing of the learning curves involved in applying the resin properly; the optimum pattern to lay down, how best to wind the Carbon Fiber onto my mandrels and the curing of the wrapped Carbon Fiber tubes that I'm looking for success in doing. It matters not what others who have never even tried such a project define as success. That doesn't even enter into the equation. One step at a time.

The subject of "Heat Retention" in the metal of the barrel is one I kept coming across with nearly every negative comment or opinion I read or viewed on video when I was doing my informal research in to Carbon Fiber Wrapping rifle barrels. At one point I came across a comment from one of the actual producers of Carbon Fiber Wrapped barrel. This person was fielding negative comments regarding "Heat Retention" due to what detractors deemed to be the "Insulating Qualities" of the Carbon Fiber wrapped around a steel rifle barrel. This person offered up the mathematical formulas to disprove or to take the steam out of the "Heat Retention" concerns they were continually being bombarded with. I can't remember the guys name. I think he was from Proof Research but it was a while ago so it may have been one of the other Carbon Fiber Barrel manufactures. I never did get to see those mathematical formulas but to me it wouldn't have mattered much cause I suck at math anyway.

"Success?" To me is learning how to actually do it myself. To get a lighter weight barrel. To get a more rigid barrel. To get a safe shooting barrel. Hopefully to get a accurate barrel. To NOT have to pay seven or eight hundred dollars to someone who in all likelihood learned how to Carbon Fiber wrap their own barrels the same way I'm doing here. One step at a time.

I don't really think that an apology is warranted here but for the sake of keeping the peace; sorry that you don't like my design. You may be even more unhappy to know that this design will be the one that I'll most likely go with as I traverse those learning curves I mentioned above.

HollowPoint

[HollowPoint]

In anticipation of receiving the information I was seeking from my inquiry to the gentleman who replied to my email at Soller Composites, I will begin turning my first Prototype Guinea Pig barrel next week. I have it laid out with a pencil but I'm going to go ahead and turn that barrel down, ream out the chamber from it's native 223 Remington to 223 Ackley Improved; just like the replacement fluted-barrel I now have on my Tikka Lite rifle.

I will follow that up by making the two Compression Nuts. I think I'll wait a while before turning the thread protector though because I want to turn it to a specific configuration; otherwise I might be able to get away with just using one of the spares I have in my storage closet. As you may have guessed by now I'll be using the pattern shown in the CAD rendering I uploaded a couple of days ago.

I debated with myself whether I should do this now or wait till I actually had the Carbon Fiber material and the Resin in hand. In the end I won that debate. :smile: The logic behind my decision was that if Soller Composites didn't come through for me after all then having a ready-to-go turned down barrel will give me more of an incentive to keep on searching for the right stuff.

I'll be taking photos of each step as I move along. This means that any older photos I have still up on other Cast Boolits threads that I've either started or participated in will have to be taken down to make room for these new photos. As it is I've already reached my allotted limit of photo space.

I'm dreaming of perfection but in reality I'm just hoping for the best I can do. It has begun.

HollowPoint

[JimB..]

Judging from your comment I tend to think that you haven't read this thread from the beginning. Sounds like you may have jumped in near my last few posts. For me "Success" is defined in incremental steps. I want to succeed in actually being able to wrap my own Carbon Fiber barrels. This means starting with these short lengths of Carbon Fiber tubes then transferring them to my turned down barrels. This to me is doable by the average joe.

Like you've alluded to, turning down and threading the barrel and the matching mandrels is the easy part as far as I'm concerned. It's the traversing of the learning curves involved in applying the resin properly; the optimum pattern to lay down, how best to wind the Carbon Fiber onto my mandrels and the curing of the wrapped Carbon Fiber tubes that I'm looking for success in doing. It matters not what others who have never even tried such a project define as success. That doesn't even enter into the equation. One step at a time.

The subject of "Heat Retention" in the metal of the barrel is one I kept coming across with nearly every negative comment or opinion I read or viewed on video when I was doing my informal research in to Carbon Fiber Wrapping rifle barrels. At one point I came across a comment from one of the actual producers of Carbon Fiber Wrapped barrel. This person was fielding negative comments regarding "Heat Retention" due to what detractors deemed to be the "Insulating Qualities" of the Carbon Fiber wrapped around a steel rifle barrel. This person offered up the mathematical formulas to disprove or to take the steam out of the "Heat Retention" concerns they were continually being bombarded with. I can't remember the guys name. I think he was from Proof Research but it was a while ago so it may have been one of the other Carbon Fiber Barrel manufactures. I never did get to see those mathematical formulas but to me it wouldn't have mattered much cause I suck at math anyway.

"Success?" To me is learning how to actually do it myself. To get a lighter weight barrel. To get a more rigid barrel. To get a safe shooting barrel. Hopefully to get a accurate barrel. To NOT have to pay seven or eight hundred dollars to someone who in all likelihood learned how to Carbon Fiber wrap their own barrels the same way I'm doing here. One step at a time.

I don't really think that an apology is warranted here but for the sake of keeping the peace; sorry that you don't like my design. You may be even more unhappy to know that this design will be the one that I'll most likely go with as I traverse those learning curves I mentioned above.

HollowPoint

I’ve been following this, in fact post #9 is mine. It seems that you’re defining success as learning something, and that happens if what you try works or doesn’t and so your initial design is largely irrelevant. It still seems unlikely to work, but I know very little and it could turn out to be the best design ever, won’t know for sure until you try it.

About the heat, the math is more complicated than I remember, but I think the insulating capacity of the carbon fiber is probably offset by it’s far lower heat retention capacity, so in effect a much much larger percentage of the energy gets pushed out the front of the barrel rather than absorbed by the barrel, so the bore cools more quickly. Probably hits practical limits as you increase the rate of fire, so for example you’d probably burn out the bore more quickly in full auto, but that’s not what you care about.

Anyway, no apologies necessary, go play with it and let us know what you learn.

Edit to add: when I said sleeve I meant sleeve and not tube. I believe that a sleeve is woven rather than wrapped, and it is not ridig. You insert your barrel, turned to a specific profile which fits snuggly, into the sleeve and then go through the curing process. Again, I know next to nothing about this so maybe I dreamt this.

[HollowPoint]

I got a chance to chase the threads on my donor barrel yesterday morning. Since I'll be using the Savage-Barrel-Nut method of installing my barrels onto the receivers I needed to extend the threads on the tang by another 1 1/8". I'm going to also be installing an additional recoil lug as well. Tikka rifles come with just a sliver of a recoil lug that fits into a shallow milled slot on the underside of the reciever. It fits neatly into the inletting of the stock but it has always looked kind of insufficient to me. I'm sure this isn't completely true cause the three Tikkas I've owned over the years have all shot very accurately but, the factory recoil lug on my rifle was made of aluminum and I could clearly see the indentations on the surface of it due to even the light recoil of the 223. I actually replaced my factory recoil lugs with a DIY Stainless steel lug last year but still, I'm going to add that additional recoil lug for the sake of redundancy.

Today I hope to ream out the chamber to 223 AI. Then I'll fish around in my stash of metal stock to see if I have any stainless steel I can use to make that recoil lug, the compression nuts and the thread protector.

I've been searching the internet for maker/seller/vendors of pre-made Carbon Fiber tubing with the correct properties and dimensions for this application. I've come across two online vendors of Carbon Fiber Tubes and I've sent out email inquiries to each. I figure that at this point in my foray into Carbon Fiber wrapping my own barrels it would be more financially feasible to buy pre-made tubes rather than to spend the money on building my own jigs and Carbon Fiber/Tow and Resin and other peripheral items I'd need to wind my own Carbon Fiber tubes. If I can't line up a provider of Pre-made Carbon Fiber Tubes that are able to withstand high heat and have a rigidity equal to or better than the stainless steel that the barrel is made of then I'll go ahead and start making plans to wind my own Carbon Fiber Tubes.

Next week will be what I consider to be, "After The Holidays." If all those email inquiries I've sent out just before and during the holiday season haven't been replied to by then I'll start making phone calls instead. I'd like to get this barrel done in a couple more months if not sooner. The weather then should be ideal for field testing.

I shall return.

HollowPoint

[HollowPoint]

Out of the half dozen email inquiries I'd sent out during the holiday season I've gotten three replies this week so far . Two of those replies sounded promising.

Unfortunately none of their listed in-stock and suitable-for-this-application Carbon Fiber tubes were of the correct dimensions. They did say that they could make some up in the dimensions and the correct heat resistance I was looking for so in my latest reply to their email replies to my original inquiry, I asked them to send me a quote for the cost of making up a very small number of such tubes for testing purposes.

Incidentally; what I'm looking for are Carbon Fiber Tubes with an inside diameter of .625" and an outside diameter of 1.0". One of those respondents makes them in any length up to 96". The other makes them as long as 105". Neither mentioned anything about minimum or maximum orders so I don't know if they are willing to make up just a couple of 12 or 24 inch lengths to begin with. I'll have to wait and see what they have to say if or when they contact me again. If they make no effort to contact me again that will be a pretty good indication that they don't want to mess with a Starry-Eyed Small-Timer like myself who only wants a small number of these Carbon Fiber Tubes.

In my mind the worse case scenario would be to order a slightly larger quantity of specified Carbon Fiber tubing only to find after the fact that it just wasn't working out. Hopefully they'll get back in touch with me cause buying pre-made tubing with the right characteristics for this barrel wrapping application would help me complete this project a whole lot faster than having to accumulate the components and the hardware to wind my own tubes.

On the home front; I'll be finishing up the machining of my donor barrel in the next couple of days. I don't want to do any actual turning down of my donor barrel until I get my hands on the correct Carbon Fiber tubes so I can get exact measurements off of them. I mentioned before that I had already reamed out the existing chamber of my donor barrel; as well as extending the threads on the tang. Yesterday I made up the new recoil lug I'll be using and today I worked on the new barrel-nut for this setup. That new barrel-nut should be done tomorrow morning. I'll take some photos at that time and post them for you all to see.

The way I picture it in my mind is; any machining that needs to be done is pretty straight forward. I think anyone with a metal lathe and a bit of lathe turning experience can do that part. The difficult part for me is having to rely on the expertise of others when it comes to the Carbon Fiber tubes aspect of this project. I have a pretty good idea of what it will take if I have to wind my own Carbon Fiber tubes. I mean in terms of Carbon Fiber material/tow, resins and the winding jig. That puts me a little farther ahead than I was when I first posted this thread. Back then I just wanted to know which was the correct resin to use. I found the answer to that and having figured this much out I would still prefer to proceed using pre-made tubes and then once I have the bugs worked out of that I can then look toward possibly making my own Carbon Fiber tubes if I decide to rebarrel any of my other rifles.

Slowly but surely things are moving forward.

HollowPoint

[HollowPoint]

Those two respondents to my initial inquires about the appropriate Carbon Fiber tubing for this application never did get back to me. One of those two respondents had recommended a specific Carbon Fiber Tube for this application but as I mentioned before, the outside dimensions were a bit too small if I were to be working with the one-inch diameter barrel blanks that I planned on using if or when I decided to re-barrel any of my other rifles.

This time out, since I'd be working with the take-off barrel from my recently re-barreled Tikka-Lite rifle; as crazy as it sounds, I was so fixated on wanting the one-inch outside diameter Carbon Fiber Tube that it didn't occur to me that my take-off guinea-pig barrel had already been turned down from the factory so that the Carbon Fiber Tubing that the email respondent from RockWest Composites had suggested would actually be close enough to what I needed for this project.

So; all of that to say, I have now ordered two short lengths of the Carbon Fiber Tube that was suggested for this particular manner of application. They will be installed in the manner I had described in my uploaded CAD rendering.

Now I wait for deliver before I can proceed any further.

On the home front; I finished up the all of the machining tasks I could without having those specific carbon fiber tubes on hand. Once they get here I can then get the measurements I need to start the lathe work that will get them down to the diameters I'll be working with. I still haven't taken those photos I mentioned. I'll try to do that today sometime but my front and back lawn is in dire need of mowing; among other things that need doing.

Also: I will be attempting to contact the moderator of this section of the forum to ask if it's possible to change the title of this thread. If it is possible, I will be asking if they can change the title of this thread to, DIY CARBON FIBER WRAPPED RIFLE BARREL. Those of you who happen to be following this thread under the existing title, please keep an eye out for that possible title change.

My original "Inquiry-Sounding" title now somehow seems insufficient or misleading in that it gives no suggestion or clue about what this thread has evolved into. Although originally it was trying to find the correct bonding agent for winding my own Carbon Fiber tubes, I have since then found that answer and in the process of finding that answer I found also that I could simply buy Carbon Fiber Tube with the appropriate characteristics instead. (which is what I've done)

I'll be back.
HollowPoint

[HollowPoint]

Here's a hastily taken and edited photo of the chamber end of my Tikka-Lite donor barrel. It's a tad blurry but it's good enough to give a good idea of what I was attempting to describe in my previous posts.
Things are moving along now so I hope to have this project done sooner than I expected. Because my Tikka rifles are both barreled using the "Savage Barrel-Nut" method it means that swapping barrels should be relatively quick and easy. I will probably have to fabricate a reciever wrench that will allow me to keep the recoil-lug in the right orientation as I screw this new barrel into place but I'm thinking that this will not be very difficult either. I just have draw up a model and convert it to G-Code, then I can machine it on my hobby mill. I have enough metal stock laying around for this.

I'll be back when the Carbon Fiber tubes get here.

HollowPoint

[HollowPoint]

No sooner that I order those tubes I mentioned in my previous post to keep this project from going idle on me then this morning I finally get a reply from one of the manufactures of Carbon Fiber Tubes that had previously contacted me. (Dean Comstock from Dragonplate Composites) I wish he'd of contacted me a day earlier but, Oh Well. I had already order tubes from his competitors at RockWest Composites.

He did have what I consider to be a bit of good news though; and that was that if need be they could make up custom Carbon Fiber tubes with an even higher heat resistance of 500F degrees. I would've preferred this higher tolerance to heat than the 250F degree level of the tubes I've already ordered. In the same way that I asked the guy from RockWest Composites to give me a written estimate of what it would cost to have some custom tubes made up and what they accepted as a minimum order; I asked this guy from DragonPlate Composites the same thing.

The RockWest guy never did get back to me when I asked him to send me a written estimate of what it would cost for them to make up some custom tubes so there's a chance that this guy from Dragonplate will also not be heard from again. Having ordered those tubes yesterday, at least now I will have some Carbon Fiber tubes I can do some testing on. I plan on running over to my local Walmart and picking up one of those cheap ten or twelve dollar pistol-type laser thermometers so I can check for myself to see exactly what kinds of temperatures I'm really dealing with when shooting my rifles in the typical way I do. If that 250 degree level of heat resistance isn't reached during one of my typical range sessions then I'll know that this will most likely do for the average-joe rifle shooter/hunter. Still, I would much prefer that slightly higher level of heat resistance offered by the 500F degree resin used to bond those Carbon Fibers into a tube.

I may post the Dragonplate guy's email reply so you can read it for yourselves to see what he had to say. In the off chance that any of you guys may consider Carbon Fiber wrapping your own barrel some day, it may help you sort out what you may need. I've been archiving any correspondence I'm having with those Carbon Fiber Tube makers who have taken the time to reply to my email inquiries. I'll be back with updates as they happen.

HollowPoint

[HollowPoint]

I finally got a reply from the guy at the RockWest Composites website. He basically suggested the very thing I had already decided to do since I hadn't heard from him in a while. That is, to try the Carbon Fiber Tubes that he had originally suggested to see if they were going to work or not. Duh.

I'm hoping that those Carbon Fiber Tubes I ordered will be here this week some time cause I have this week free to do the remainder of the lathe work I'd need to do to get this project moving along a bit faster. This morning I pre-drilled and bored out the metal stock that I'll be making the compression-nuts out of but I really can't do any more than that till I have those Carbon Fiber tubes in hand.

This same individual (Rylan) also gave me a general price of what it would cost for them to work up a Carbon Fiber Tube that may meet the requirements for this Barrel Wrapping application. Anyone care to guess the initial cost of having them put together a pre-made Carbon Fiber tube with all of the qualities needed to withstand the demands of this application?

$2,300.00 just to begin with. He didn't mention any minimum purchase amounts. This is just to get the ball rolling with his people to figure out exactly what resin to use and how to best wind the Carbon Fiber Tow in order to get the optimum rigidity out of it.

When I was gathering information about the materials I'd need to make my own Carbon Fiber tubes (minus the correct resin cause I was still looking for that information at the time) the total cost wasn't anywhere near that amount. Now I've found a couple of sources for the correct High-Heat resistant resin so even adding the price of those resins, the curing oven, the vacuum pump, the shrink tape and other peripheral materials it still wouldn't come close to the twenty-three-hundred bucks he mentioned. I understand they have overhead; probably lots of it too but, wow. And I had already come across at least one online engineering write up having to do with the optimum winding pattern to maximize the rigidity of a Carbon Fiber wrapped barrel so, it's not like that information isn't already available.

It may be that the guy from DragonPlate Composites will contact me eventually as well with similar prices. I really won't know until he decides to get back to me. If I had to choose between the two, at this point in time I think I'd choose the DragonPlate guy; mainly because the bonding resins they use are good up to 500 degrees F.

With any luck, after testing the incoming Carbon Fiber Tubes that are bonded together with resins said to resist heat up to 250 degrees, I'll find that they are totally sufficient for this application. If the kind of shooting I generally did involved rattling off round after round in a short amount of time, then I'd be looking for an even higher heat resistant resin but, I'll just have to wait and see how the first round of testing goes.

Incidentally; while I was informally gathering information on the subject of Carbon Fiber Barrel Wrapping rifle barrels I also did a search on, "How Hot A Rifle Barrel Got When Fired Multiple Times?" One of the things that this internet search brought up was a video of a guy who wondered the same thing. In this video this same guy was shooting an AR platform rifle with 30 round magazines of full power 223 ammo. The barrel of his rifle was one of those factory thin barrels if I remember correctly.

With the first mag-full he rattled off all thirty rounds in less than a minute and then he put his laser-thermometer to the barrel at different sections of the barrel; the chamber end, the muzzle end and near the gas block. If I remember correctly it measured about 175 degrees. He did the same thing with the second mag-full immediately after taking those temperature readings. I'd have to re-watch that video to be sure but I'm thinking the temperatures were in the three hundred degree range after rattling off that second mag-full. The third mag-full of rounds took the temperature of that AR barrel even higher still. This was all within the span of about five minutes or less.

In a typical range session where I'm working up loads I'll generally fire about five rounds in the span of five minutes or so. I mention this because if this guy on the video's gun barrel temperatures reached the 170s after rattling off 30 back to back rounds, there's a very real possibility that the 250 degree heat-resistant resin used in making the tubes I've ordered will be perfectly fine for what I have in mind. We shall see.

I'll be back as new information becomes available.

HollowPoint


https://youtu.be/DRMI7wAfdLg

[HollowPoint]

I didn't think the Carbon Fiber Tubes I ordered would show up until later this week. Because of this I had made plans to do some "Retired-Guy" stuff tomorrow. I made plans to go trout fishing tomorrow morning and I'm not inclined to cancel those plans now.

I was surprised to see that I had been shipped out one 24" long piece of Carbon Fiber Tube rather than the two twelve inch pieces I expected. The listing for this particular type of CF tubing stated that they were sold in 12" sections. No matter. This may actually work in my favor. If it turns out that my typical way of shooting doesn't max out the temperature rating of the resin used to make these Carbon Fiber tubes, if I decide to Carbon Fiber wrap another barrel it means that I'll only have to order one more 12" section of the same tube.

Below is another hastily taken photo of this project's progression. I ordered this Carbon Fiber Tube un-sanded. What this translates to is that the outside diameter, although listed as being .91", actually varies from .9125" or so, to .9093". If it had been sanded there at the factory it would have come in a uniform outside dimension that matched the specs on the list of various tube sizes. Using the factory contoured take-off donor barrel from the Tikka T3 Lite rifle, I can work with these dimensions even though the outside of the tube isn't perfectly uniform. Heck, I may decide not to do anything more with the outside surface of this tube until I've had a chance to test it's heat resistance and rigidity when installed on the rifle.

A close look at the surface of this tube shows a series of right-angle lines from edge to edge on the tube. These lines were imprinted on the surface of the tube when the shrink tape was applied for the initial curing process. The photo really doesn't do the Carbon Fiber wrapping pattern any justice. In my hands I think it looks kind of cool. I had previously enlarged the inletting of my rifle stock where the barrel sits in order to accommodate the bull-barrel I have on it now so if I leave the outside diameter of the CF tube as it is, it too should fit pretty well into the stock with no further fiddling.

I'm not doing any gunsmithing tomorrow. I'm going fishing instead. I'll be back on Thursday to start turning down my donor barrel to accept this Carbon Fiber Tubing. Wish me luck.

HollowPoint

[HollowPoint]

By now most of you following this project have had a chance to take a look at the CAD Rendering I uploaded a few days back. One of the three different methods of going about this DIY Carbon Fiber Barrel wrapping project was shown in that uploaded image.

The other two ways that I was considering as a way to tackle this project were: (I'm sure there are other ways too. This is just the three ways I was considering)

(2) Use basically the same method of installing a pre-made Carbon Fiber tube except that rather than having two Compression-Nuts; one at the muzzle and one near the center of the barrel's length, this second method would be to just use a single Compression-Nut at the muzzle end of the barrel; provided I could get a long enough pre-made Carbon Fiber tube made with the right characteristics.

(3) The third method of Carbon Fiber wrapping a rifle barrel would entail milling down the diameter of the barrel and leaving about three inches at the chamber end unturned and about an inch and a half of unturned barrel at the muzzle end. The Carbon Fiber Filament would then be wrapped, directly onto the turned down section of the barrel until the height of the Carbon Fiber material was level with the chamber and muzzle ends that had not been reduced or profiled in diameter. Any profiling would be done after the Carbon Fiber curing process.

Well, I fully intended to go with my first choice; and that was to use two separate compression nuts; one at the muzzle and one near the center of the barrel's length. I even went so far as to do all my lathe work with that in mind. I profiled my donor barrel exactly as I'd planned but after I'd finished the lathe work on that barrel I got to thinking a bit more about it and, since I'd been sent out a full 24" length of pre-made Carbon Fiber tube rather than the two twelve inch pieces I'd expected to get, I decided to change my plans and just use one full length piece of tubing with one lone Compression-Nut at the muzzle end.

I should have the Compression-Nut done this weekend along with the Thread Protector. I've already cut that 24" length of pre-made Carbon Fiber tube I ordered down to the correct length. I also milled some breather-holes into it to allow for ventilation to aid in cooling the barrel with this method of Carbon Fiber wrapping a rifle barrel. I'll take some more photos tomorrow and hopefully I'll be able to edit them and upload them on Sunday.

It looks like I did a decent job of turning down my donor barrel because the tube slides right into place with no slop and little force needed to get it seated into position. I don't want to get ahead of myself but, now I have to determine how much torque I'll need to apply to my compression nut to get the optimum rigidity out of this DIY Carbon Fiber wrapping setup. If any of you have any good suggestions maybe you can share that info with me. In the back of my mind the torque specs of the Savage Barrel-Nut might be a starting point but I haven't decided yet.

HollowPoint

[ulav8r]

Don't know how much but concerns are: Don't crush tube - do you need to allow for barrel stretch cold to hot - will accuracy vary with torque applied?

[HollowPoint]

Don't know how much but concerns are: Don't crush tube - do you need to allow for barrel stretch cold to hot - will accuracy vary with torque applied?

These are all valid questions I've asked myself as well. I've been looking into the amounts that various materials expand when subjected to heat and how much they can be expected to expand.

When I read up on some of the trials and errors of a guy named Mike Degerness I got a general idea of what to expect in regard to heat induced metal expansion. This guy Mike Gegerness is one of the pioneers of Carbon Fiber barrel wrapping. The piece I read about this guy was actually an interview done by some gun-writer some time back. In this article it touched on a number of things including the types of specialty resins they eventually formulated, the safe amount of thickness of the barrel walls as it related to the bore diameter, allowances for expansion and the exact angles used when wrapping the Carbon Fiber filament around the turned down barrels; among other things. No mention of exact torque specifications were made though. I guess this will be something that one has to figure out on their own.

If I can find some information about thermal expansion of gun barrels I think that may help a bit. I suspect some trial and error will still be called for. "Will accuracy vary with torque applied?" I'm thinking it probably will if my Compression-Nut is over-tightened or under-tightened. If I can find the sweet spot, in theory this should mitigate any accuracy fluctuations caused by a hot or cold barrel.

This may be a poor analogy but, if you are familiar with concrete forms; when those long and huge "T-Shaped" bridge rafters are made, they are formed around rebar cables that have been stretched tightly from end to end. These concrete forms are poured around those stretched rebar cables and when the cement has cured, the tension on the rebar is released and it constricts as far as it is able within the concrete structures. This further strengthens the forms because it also has the effect of constricting the concrete that the rebar was imbedded into.

In a similar manner, when my Compression-Nut is tightened down against the longitudinal rigidity of the Carbon Fiber tube it should have the minor effect of somewhat stretching the barrel-metal taught. As thermal expansion occurs the section of the barrel in between the Compression-Nut and the shoulder on the chamber end of the barrel should in theory cause enough additional tension to maintain a straight bore; which in turn (I hope) will enhance accuracy. Whether it actually plays out this way is yet to be seen.

It will be a few more days till I do any actual assembly of my barrel parts. This will give me some time to look for more information on this aspect of this DIY project.

HollowPoint

[HollowPoint]

I found those equations I needed to help me figure out what I can expect in the way of Thermal-Expansion of the 416 Stainless steel that my donor barrel is made of.

It gave me a headache just looking at those numbers. I suck at math so trying to figure out what those numbers actually meant was like trying to read Egyptian hieroglyphs. Eventually, after veiwing several YouTube videos on the subject I think I figured it out.

The Thermal Expansion coefficients for just about any material can be found online with a simple internet search. The Carbon Fiber Tubes also have their own set of numbers so the tricky part for me was to remember to subtract the values I ended up with for the Carbon Fiber tube from the values I got for the 416 Stainless steel. If I worked those equations correctly it means that the maximum temperature that the Carbon Fiber resin is rated for, (250 F) my 18" long barrel can be expected to expand in length by .012105"..

As I've already admitted, I SUCK AT MATH so, to confirm the numbers I came up with I'll be doing a couple of experiments next week. One experiment will be to put my 18" barrel in the freezer over night and measuring it again to compare the length I get to the existing ambient-temperature length. I keep saying that it's 18 inches long but to be more specific it measures 18.375" long. I still have to cut the eleven-degree crown on the muzzle so that will shorten my length a bit but I'll do that after I've mounted the barrel to the reciever.

The second experiment will be to take my heat gun and heat the barrel up to 250 F degrees if I can (or as hot as I can get it with the heat gun) and then take another measurement. If the barrel does in fact shrink in the cold and expand in the heat by the amounts I've calculated then it will be a good indication of what the appropriate amount of torque should be that I'll be using to tighten up my Compression-Nut against the Carbon Fiber tube.

Why only go up to 250 F degrees in my experiment? Because, the resin that the Carbon Fiber tube is made with is only rated up to 250 degrees F. If the barrel were to get any hotter and expand any further it wouldn't really matter cause by then the Carbon Fiber tube will most likely have failed or started to fail.

If these experiments give me the results I've calculated, I figure that I can heat the barrel up again to expand the length again; then let it cool to just below 250 F degrees; after which I can slip the Carbon Fiber tube into place then torque the Compression-Nut to a bit past the point of being snug. It's not very scientific but after the barrel has started to cool off the metal should contract close to it's original Ambient-Temperature length. The only thing keeping it from fully contracting to it's original Ambient-Temperature length will be the Carbon Fiber Tube wedged between the Compression-Nut and the shoulder at the chamber end.

I'll have to run over to my local Walmart store to pick up one of those cheap laser thermometer guns they sell.

Below are a couple more hastily taken photos of what I've gotten done so far. I think I'm done with the machining part of this project. Next up will be the shooting tests to see how well this Carbon Fiber Tube holds up and what effects it has on accuracy.

HollowPoint

[HollowPoint]

As most of you already know Thermal-Expansion takes place when the barrel of our guns get hot. There is also the reverse phenomenon that occurs when the metal of the barrel cools down. In order to arrive at a optimum torque value for the Compression-Nut of my DIY Carbon Fiber wrapped rifle barrel project I decided to undertake these tests. Phase one involved just sticking my donor barrel into my refrigerator freezer over night and then measuring any difference against the original Ambient-Temperature length of that same barrel.

I've referred to it as "Phase One" to differentiate it from the second part of my Thermal Expansion test which will require the use of that laser thermometer I mentioned in my previous post. I did run down to my local Walmart only to find that although they have tons of those hand-held pistol type laser thermometers on their website, they have no such items in their stores; so, I ordered one off of amazon thinking that it would be here in a couple of days just like all the other stuff I've ordered off of amazon. I found out after the fact that the thermometer I ordered was being shipped to me from China. This means it won't be here for a couple of weeks. I could have also run over to my local HomeDepot and bought one but I'm afraid the cheapness in me would not allow me to pay fifty or sixty dollars for something I could get for 12 dollars; and those more expensive models were most likely made by the same little Chinese kids as the cheaper models.

I took some photos of my cold barrel Thermal Expansion test too. I'll upload those when I get closer to testing with the laser thermometer. I was surprised that this frozen barrel test yielded any results but, it did. With the naked eye I really couldn't tell any difference between the lengths of my barrel at Ambient-Temperature and the same barrel frozen over night but, believe it or not there was a very slight difference. In my mind this means that when my laser thermometer arrives I'll be able to get some fairly accurate numbers as far as the differences in length I can expect when I shoot my barrel to a certain temperature range. I'll be interested to see if these differences come close to the numbers I came up with by just doing the math.

The heat expansion test will be as simple as I can make it. I plan to secure the chamber end in a vice and then I'll place my digital calipers against the muzzle end; after which I will proceed to use my hot air gun to heat the barrel. If it works as I hope it will the barrel expansion should register on my calipers even if it's a miniscule difference.

I contacted the folks over at RockWest Composites to see if they could give me the Coefficient of Thermal Expansion numbers (CTE) for the Carbon Fiber Tubes I bought from them. I figured that when they developed their tubes they did these tests as a matter of their process; Not So. The guys there didn't know either. They did offer to run those test for me though. Anyone care to guess what their generous offer would cost? I'm not kidding; they offered to run those test to find out the CTE of these specific tubes for -wait for it-; one-thousand freaken dollars. I think I'll just run my own tests. If I can't figure out the CTE numbers for these Carbon Fiber Tubes then I'll use the generic numbers I came across when I did my internet searches for this information. It is said that the Thermal Expansion of Carbon Fiber tubing is up to "Three Times Less Than Steel." It depends on the epoxy resin being used to make the tubes.

If I get impatient with waiting for that laser thermometer to arrive I may break down and start looking locally for another cheap one. If I find one I'll just send the amazon thermometer back for a refund. Maybe craigslist has something that will work. Why So Cheap? This whole DIY Carbon Fiber barrel wrapping project is a budget project. One of the main reasons I'm doing it is to find a way to not have to pay those incredibly high prices for a Carbon Fiber wrapped barrels from one of the few makers that sell them. Waiting for a cheap Chinese laser thermometer to arrive in the mail is not that big of a deal for me. I just hope you guys can hold out till it gets here because the more I work on this project, the more I believe it's actually going to work.

HollowPoint

[HollowPoint]

I'm still waiting for my laser thermometer to show up. I checked into it and if I'm really lucky it will arrive next week some time. Since I thought I'd be on hold until early or mid February waiting for this thermometer to arrive I agreed to help a friend out with his vintage pickup truck. What this means is that even if my laser thermometer does happen to get here next week, I'll be busy helping a friend; so, it will be a couple of days later till I can get back on this project.

In the mean time, I thought I'd show you a bit of the email correspondence I've had with the guy over at RockWest Composites. I don't want it to come off appearing negative because this same guy has been gracious enough to reply to all of my email inquiries. That's far more than I can say about any of the half-dozen other composite companies I contacted. Besides that I'm sure that any testing that might have been done by his people, would have been done using high dollar methods done by highly paid people.

This email correspondence is in regard to the Coefficient of Thermal Expansion numbers associated with the Carbon Fiber tubes I ordered from them. As I mentioned in my previous post, I'll be running the tests myself instead of paying to have them done. I'll be using a simple high-school-science testing method to arrive at the numbers I'm looking for. I'll be doing the same with the donor barrel as well. I just need that laser thermometer in order to get started with it.

HollowPoint


Hi Rylan:

Our Carbon Fiber Barrel Wrapping project is moving along a bit faster now that I received the Carbon Fiber tubes I ordered from you guys. I’ve been doing some thermal expansion calculations on our donor rifle barrel in order to arrive at an optimum torque specification for torqueing down the Compression-Nut we’ll be using in our design. Once we were able to find the right coefficient numbers for the 416 Stainless Steel rifle barrel that part of our calculations went by fairly quickly.

My reason for contacting you again was to ask if your engineers had worked up any thermal expansions coefficient numbers for the specific type of Carbon Fiber tubing I purchased from you. I’ve found various slightly differing coefficient numbers of Carbon Fiber composites online but it seems that the coefficient numbers that come up slightly different from one another depending on the type of resins used to bond the Carbon Fibers together.

Are you able to supply a specific thermal expansion coefficient number for the type of Carbon Fiber Tube I purchased from RockWest Composites? Once I’ve worked up those numbers I’ll be able to go about assembling the barrel and installing it onto the rifle reciever for field testing.

The tubing I purchased from you is as follows:

TUBE - FILAMENT WOUND - UNSANDED - 0.625 X ~0.91 X 12 INCH - SOLD BY THE FOOT - AVAILABLE UP TO 108 INCHES
Sku: 35045-U

I’m hoping you’re able to reply sooner rather than later, otherwise we’ll have to move forward using generic Carbon Fiber coefficient numbers. I’d rather use the specific numbers associated with the Carbon Fiber Tubing I ordered from you. Thanks in advance.


From: Rylan Hayes
Sent: Monday, January 20, 2020 11:29 AM
To: Tim M.
Subject: RE: Searching for premade Carbon Fiber Tube but Clueless about which one

CTE of composite tubing or carbon fiber more specifically is very LOW…

We sell a very highly engineered tube product called ZTE that has guaranteed CTE values - https://www.rockwestcomposites.com/round-tubing/round-carbon-fiber-tubing/zte-carbon-tubing

We might be able to test the SKU listed below in our thermal testing chamber but the cost might be $1k per test, we would not take this cost on ourselves unfortunately. I would also have to find out if we are able to test that specific diameter too. Currently we only test tubes @ 2” for one specific customer.


Following is the simple test I'll be doing on both the donor barrel and the piece of CF tube I have left over from cutting that 24" length down. I'll be using a combination of digital calibers and dial indicators. One of my indicators measures at .0005 and the other is an .001 dial indicator. Also; I won't be using a Bunsen burner; I'll be using my heat gun.


https://youtu.be/YlE8jfXne8E

[HollowPoint]

I called my friend earlier today. This is the guy I mentioned about promising to help him out with his 1930 Model A pickup. It looks like he won't be able to do that work next week so that means I'll be free to pursue the work on my Carbon Fiber wrapped barrel; provided I get my recently ordered laser thermometer in the mail next week.

I did check into that delivery again today and I was given an estimated delivery date of January 27th. It would be awesome if it got here on Monday. That would give me the rest of the week to play around with this project.

I'd forgotten that since I would be utilizing an additional recoil-lug I'd have to work on the bedding to accept this added component. I did the bedding this morning. I'll be letting it sit till tomorrow some time as it fully cures. I assembled everything just hand-tightened in order to do that small amount of bedding. It's all fitting together nicely with no further messing around with inletting to fit the new Carbon Fiber barrel.

Before taking my Tikka apart I re-weighed it to make sure I was giving you the correct information. As it was, wearing the 16" spiral fluted bull barrel I installed last year and with the scope in place and the magazine installed it weighed 8.3 pounds. That's pretty heavy for a rifle called a "Tikka-Lite" rifle. It was slightly lighter in its factory configuration. The bull barrel really put some weight on it.

When I assembled this same rifle with the Carbon Fiber barrel in place wearing the same scope and magazine it weighed in at 6.11 pounds. So, the Carbon Fiber barrel shaved a couple of pounds off of the overall weight and it also did wonders for the balance of the gun. This equates to a not-so-Nose-Heavy rifle when I put the suppressor on.

Some of you guys have already seen photos of this same Tikka-Lite rifle wearing the spiral fluted barrel but I decided to post one last photo of it as it was before I took it apart. Once I get the new CF barrel mounted it will give you a good comparison between the two. Also; I should mention that I spent about an hour this morning removing the tan colored paint that I'd painted it with when I installed the spiral fluted bull barrel. I'll leave the stock as it is for now but the barrel and receiver is stainless steel with the black Carbon Fiber tube as contrasting color.

HollowPoint

[HollowPoint]

My Laser Theremometer Showed Up Today!

Perfect timing. I got the little bit of bedding I needed to do all finished up. I also did a slight mod to my action-wrench to hold the additional recoil lug centered as I screw everything down. Now all I need is some AAA batteries to get the darn thing to work. I guess I'll have to run to Harbor Freight first thing tomorrow morning.

I hope to have the Thermal Expansion tests done and the gun assembled by the end of the week. Things are looking up.

HollowPoint

[HollowPoint]

It actually did work but not by going with my original plan of using my heat-gun instead of a Bunsen burner or an open flame. The ambient temperature of the room and the barrel before applying any heat was 61 degrees F.

I was only able to get the temperature of my donor barrel up to 126 degree F. It seemed that the column of heated air being shot out of my heat gun was hottest at the center of that column of air. The air at the periphery of that heated column of air tended to begin the cooling process as soon as I moved the heat gun in any direction.

At 126 degrees the .0005" dial indicator measuring any outward expansion had still not moved. The digital calipers measuring the longitudinal expansion of my barrel started moving as soon as I got to about 75 or 80 degrees F.

At the 126 degree mark my digital calibers had moved to .00065". It was painfully slow going. I couldn't get it past that level of heat so I decided to bite the bullet and break out my little propane flame thrower. I fired it up and lightly but rapidly skimmed that flame on the length of my barrel. I made just a few back and forth passes cause I really didn't want to apply an open flame to my donor barrel.

With just five or six back and forth passes my digital calipers climbed to .022". My (.0005") dial indicator also moved to near the midway point between the Zero hash-mark and the hash-mark right next to it. I put the laser thermometer on it to see what the temperature was and it read 75 degree. I knew that couldn't be right. The instructions that came with this cheap little laser thermometer stated that shinny surfaces tended to give false readings. This had to be what was happening. Those same instructions also stated that if I was getting what appeared to be false readings that I could place a piece of masking tape or electrical tape on the surface of whatever it was I was measuring the temperature of and once that tape reached the same temperature as my barrel, the thermometer should then give accurate readings. The tape was meant to mitigate any reflection from a shiny surface.

The electrical tape just melted right off and the adhesive on the back of the masking tape I tried didn't fare any better. My concern at that point was to NOT over heat the barrel. I don't think I even came close to doing that but I was not able to get the accurate readings I was wanting to get at the higher temperatures. It was a good enough indication to me that I could go ahead with original idea of how I'd go about torqueing down my Compression-Nut. I thought to myself after that fact that I should have just tied my melting-pot thermometer to the barrel and at least have gotten an indication of the barrel temp. I'll do that when I go to put it all together.

I'll mount and head space the barrel. Then I'll put it back into my heating setup and when it gets to the same .022" length of expansion I'll then slip the Carbon Fiber Tube into place and torque my Compression-Nut just past the point of being snug. In my mind, that should give me a securely torqued down Compression-Nut with sufficient torque to compensate for this kind of expansion under my normal shooting range or hunting sessions.

I had also planned on doing the same to the short length of left over Carbon Fiber tube I have. I also wanted to determine the CTE of that as well but if my laser thermometer won't give me anything resembling an accurate reading on my donor barrel I'm not really willing to shoot an open flame at the surface of that tube cause I'm pretty sure, without knowing for sure what temperature it's at I'll end up just ruining the tube.

I took a few photos of this experiment and some video but I haven't had a chance to edit it down to be able to upload it here or to my Instagram account. I'll try to post those pics by the end of the week. I want to use the rest of this free week to get this thing all put together. I'd love to be able to take it to the range within the next couple of weeks.

I'll be back.

HollowPoint

[HollowPoint]

Here are some still photos of the results I got from my thermal expansion testing. I went ahead and used my final linear expansion results to work backwards with my mathematical calculations and it appears that by using my propane torch I had managed to get my donor barrel to approximately 225 degrees Fahrenheit.

I need to issue a correction here. In one of my previous post I stated that the Coefficient of Thermal Expansion numbers I'd found online for 416 stainless steel was, "6.5 X 10 -6. (that's six-point-five times ten to the negative six) That was incorrect. I had mistakenly mixed up the number "6.5." It was actually 5.6; and in this case, these particular CTE numbers were used if the temperatures went up into the 600 Fahrenheit range. I only went up into the low 200s so the numbers I used then were 5.5 X 10 -6.

If that sounds confusing, I agree with you. Now you know why I suck at math. Anyway; I got the information I needed. Now I can proceed to mount the barrel, do the headspacing and then heat it up again in order to secure the Carbon Fiber tube into place.

Here are those photos. I hope they make some kind of sense to you all. The short videos I made when I did these tests will take me a little bit longer to edit. I have to whittle them down to one minute apiece in order to upload them to my instagram account. I won't be uploading anything longer than that to my YouTube account until I've had a chance to do some field testing with the Carbon Fiber barrel in place.

By the way, here is the link that I got my CTE numbers from. You may have to scroll down a bit to find the, "Mean Coefficient of Thermal Expansion" numbers but that's where I got my numbers.

https://www.ulbrich.com/alloys/416-stainless-steel-uns-s41600/

HollowPoint

[HollowPoint]

I finally got it all put back together again. I then weighed it again both with and without the scope in place. Without the scope it still weighed in at 6.11 pounds. With the scope in place it added one and a half pounds to get the total weight to 7.6 pounds. So, with an 18" Carbon Fiber barrel in place I was able to shave about a pound and a half off of what it was before when wearing the 16" Spiral-Fluted bull barrel in place.

I had a heck of a time getting the headspacing just right this time around. I must have put it together and then taken it apart three times before I figured out what was going on. If I weren't already bald-headed I would have pulled all my hair out trying to figure out why I wasn't getting the head-spacing to work for me. I'd try cycling cartridges after each assembly and some would cycle just fine and others would not. My No-Go-Gauge was doing exactly what it was supposed to do but I got no repeatability when cycling various cartridges. It turns out that some of my reloads had the primers sitting flush with the bottom of the case and those that were giving me problems had the primers sitting just above the surface of the base of my reloads. Rookie mistake.

I torqued my Compression-Nut down exactly the way I'd described in my previous posts. I heated the barrel again till it expanded length-wise as before; this time I let it expand to .023" then I quickly slipped my Carbon Fiber tube into place and torqued it down just past the point where it felt snug. The one mistake I made when doing so was to not hold the Carbon Fiber tube firmly enough as I tightened that Compression-Nut down.

The Carbon Fiber tube was perfectly indexed so that my vent-holes were at top dead center in relation to the reciever but when I tightened that compression nut the tube spun clock-wise along with the Compression-Nut so my vent-holes ended up slightly off center.

I have a pretty extensive internal library of cuss words to draw from in situations like this and I was able to pull out a few of those choice words when I noticed what had happened. To find some sense of consolation I reasoned within myself thinking, "Well, this is just a prototype to see if this Carbon Fiber Wrapping project is really going to work or not." So I opted to leave it as it was for now. If by some chance I manage to heat up that barrel to the point where it expands just enough for me to simply use hand pressure to spin it upright then I'll do that. Shooting my range sessions the way I usually do, I really don't think that the barrel will ever get that hot. Maybe if I shoot alot during the summer months. I'll just have to wait and see.

This time around before I heated up my donor barrel I had sprayed it with some flat-black spray paint in certain areas so that my laser thermometer would give me some useable readings. That seemed to work out a whole lot better than trying to take temperature readings off of a shiny stainless steel barrel. I also tried putting my melting-pot-thermometer right against the barrel as I was heating it. I tied it onto the barrel with some thin strands of copper wire. That was a waste of time. The needle on that analog thermometer never moved, even while the Thermal Expansion of the barrel had reached .023".

After assembling the rifle for the last time I did make it a point to mask off the base of the barrel and the muzzle so I could paint it black. This wasn't done for any aesthetic reasons; I did it so I could take my laser thermometer to the shooting range and take some reading off of those black areas after each shot. Now it's just a matter of finding the time to get to the range for the testing. I'm hoping for the best cause I deliberately tried to do my best to keep everything as perfectly concentric as I could. All my rifle components were put together using the same torque specs I'd used when I previously/initially rebarreled this same rifle and it turned out just as accurate as it was in it's factory configuration.

I took only a couple more pics of the assembled rifle sitting on my postal scale. I'll try to post those a bit later.

HollowPoint

[HollowPoint]

Here are three more pics of my assembled Tikka Carbon Fiber Wrapped barrel project rifle.

These photos too were taken and edited in a hurry just like all the others. I'm hoping that they'll tide those of you over who have been following this project thread until I can get to the shooting range for some testing.

I really think it's going to work, provided I don't over-heat the barrel and cause it to thremally expand beyond the amount of torque I applied to the Compression-Nut. Having tested for myself the way that the barrel expands longitudinally as it reaches certain temperatures, I don't believe I will experience alot of point of impact shifts but, that is what the range testing is expected to show.

Another thing the range test will show is, if I do reach the temperture limits that the epoxy resin used to make the Carbon Fiber tube, will the tube start to de-laminate or show any kinds of adverse affects from the combination of heat and the pressure induced from the Compression-Nut?

I'm thinking that if I do get the temperature up that high the accompanying length-wise Thermal Expansion should mitigate any of the crushing pressure induced by the torque of the Compression-Nut but, it's just one more thing to keep an eye out for during testing.

I'll be back with more photos and results after I've had a chance to get to the range for testing. Thanks for sticking around guys.

I almost forgot. I was able to shrink those short videos I made of my Thermal Expansion test down to uploadable sizes to my Instagram account. I'll try uploading them tonight. They may make absolutely no sense to anyone of the very few people who follow me on instagram cause I've not mentioned this project to anyone except for you guys here on the Cast Boolits forum. I'll be removing those same short videos a day or two after I upload them. I just wanted to show you guys here what I was trying to describe with the written word. When you write a description down it tends to make things sound a whole lot more complicated than they really are.

HollowPoint

[cwtebay]

That's awesome!!! Thanks for sharing your journey with this endeavour!! Hope it shoots the lights out for you!

Sent from my Pixel 3 XL using Tapatalk

[HollowPoint]

That's awesome!!! Thanks for sharing your journey with this endeavour!! Hope it shoots the lights out for you!

Sent from my Pixel 3 XL using Tapatalk

Thanks cwtebay:

I'm pretty sure it will shoot. What I'm not sure about yet is if it will shoot consistently and accurately. If it does then the Cat Will Be Out Of The Bag; so to speak. It will mean that for those who have access to a metal lathe and some common sense there will be no need to pay upwards of 800 dollars-plus for a Carbon Fiber barrel put together by one of the big names in that line of the gun parts industry.

I really hope that this long winded thread didn't come off sounding like I was trying to talk folks into going the DIY route when considering a Carbon Fiber barrel for one of their rifles. If you have the means to do so it would probably be best to just purchase a pre-made Carbon Fiber barrel from one of the top names in that field. By all accounts they put out some top notch stuff.

The problem for me was that you can buy the very best Carbon Fiber wrapped barrel that money can buy but then you have to go looking for a competent gunsmith to install it, if you are unable to do it yourself. Beyond that there are a myriad of variables that will effect how good a given Carbon Fiber barrel will shoot. You've just laid out a wad of cash for a new barrel, then an additional amount for a competent gunsmith, then more money for your load workup and then there's the competence of the person pulling the trigger to consider; and on and on it goes. It's to easy to spend alot of money and end up with little to show for it.

I'm not insinuating that I'm that competent at any or all of those things, it's just that I don't have that kind of expendable income so I thought I'd try developing a way that would allow me to do it myself with a minimal outlay of hard earned dollars. So far it's looking like it's going to work. Only after testing will I know for sure. It may turn out that a different type of Carbon Fiber tube may be needed; or a tube made with an epoxy resin with higher heat resistance or wrapped on a mandrel at a more optimum angle to increase rigidity or both. I'll just have to wait till my range sessions testing is done to know for sure.

I'll be back to dredge up this thread when I get that far along. Next week I think I'm going to be helping out that friend I mentioned in a couple of other posts. If I'm lucky he'll be to busy again next week to do the work on his truck again so I can use that time to head to the shooting range.

HollowPoint

[HollowPoint]

I was able to upload snippets of the short videos I made of my Thermal Expansion tests. I say "Snippets" cause they were already only a minute long.

I wasn't able to upload them in their native Window Movie Maker format so I had to go online and download video converting app that would allow me to convert the format from WMV to MP4 in order to be able to upload them to my Instagram account. Unfortunately the app download only came as a rudimentary version; which meant that it would deliberately only convert one third of the overall video being converted.

This is done to give you an incentive to buy the full app with all of it's features. Yea; I'm not buying the full version for an upload that I plan on taking down in a day or two but I did manage to upload enough of those short vids to give you all an idea of what I was getting at. Following is the link to that upload for those who may care to take a look. It's a poorly done couple of videos but it's all I got to show you at this time.

https://www.instagram.com/p/B8Am6Lxhxn9/

HollowPoint

[HollowPoint]

I finally made it to the shooting range today. My friend with the truck that needed fixing wasn't able to make it again this week so I was a free man.

Fortunately I had already loaded up a box full of ammo I'd put together for load-workup meant to be shot with my previous Spiral-Fluted bull barrel. I also had some medium power loads I'd made up for fire forming purposes that I used as sighters just to get me on paper.

I had no illusions of going to the range and stacking bullets at a hundred yards right off the bat. I'm generally not that lucky. It takes me two or three range sessions to get dialed in. My first 15 or 20 fire forming loads were four to six inches off the mark. I kept over clicking my 1/4 MOA turrets so that rookie move made me end up shooting just as far off to the opposite side of my aim point. I finally got that centered so I moved out to 100 yards.

With the rifle now being as light as it is I had a hard time keeping the cross-hairs on the bullseye. I couldn't believe what a difference that lighter weight made in steadying my aim. The fire forming rounds were made up of some left over 55 grain Dog-Town factory blemished bullets I had in my storage closet for God knows how long. Those were my medium power loads and they were all still in the 223 Remington brass case configuration. I had twenty-five 50-grain soft points and 20 rounds of 45-grain soft point all on top of Benchmark powder.

Even as unsteady as that light rifle was I managed to get a couple of MOA groups out of the 50 grain bullets. It wasn't until I'd just about fired all my ammo that I finally figured out how to best mount and hold the rifle to get some better accuracy. I had to shoot it like it was a pellet gun to get tighter groups. The 45 grain soft points gave me the best groups of the day; and, they did so at the highest charge weight I'd loaded up. For me this means that they would also be the highest velocity of the bunch too.

I had my Film-Through-Scope TactaCam camera with me and I did get some video of it but my 16 power scope and the poor quality of the video this camera delivers made for some not so impressive video captures. Still, I did get some video that I'll be uploading. I just have to split it up and edit it down to one minute snippets in order to be able to uploaded for your viewing. I also took photos of my targets before I took them down. When I got home to take a look at them they were no where to be found. I did keep those targets for future reference so I'll have to just snap some pics of them to show you.

Initial cold-bore temperature of my Carbon Fiber barrel before firing any shots was 50.9 degree Fahrenheit. I'd fire three of those fire forming cartridges and then take temperature readings at the chamber end, at the muzzle and through one of the small oblong breather holes in the Carbon fiber Tube. After each three shots I'd measure in the same locations. After the first three shots the temperature went up to 53.2 degrees. I noticed that at each location that I put the laser thermometer on the temperatures were different from one another so I then started just recording only the highest measurement.

After nine rounds fired the temperature climbed to 72 degrees. Then after firing the last fire forming round -number 15- the temperature measured 84 degrees. Each three shots in succession were spaced no more than about 30 seconds apart or however long it takes to cycle the action. It took slightly longer to load three more rounds into the magazine then insert it into the reciever for the next three shot volley.

Ambient temperatures were what this native Arizonan considers to be a cold morning. This most likely contributed to the barrel not heating up as much as it might have if I were conducting this test in the dead of summer. At any rate, after firing that last fire forming round the firing line went cold to give shooters the chance to run out and change their targets or do whatever they needed to do before the next session started up. By then my rifle barrel had cooled down to a measured 65 degrees Fahrenheit. After the sixth round of the new shooting session it was back up to 83 degrees. After the ninth round it was 94 degrees; 12th round it went to 100 degrees. After twenty rounds fired my laser thermometer never registered anything hotter than 105 degree Fahrenheit. It kind of left me wondering because I thought surely it should have gotten hotter than this by now but, I don't really know. I've never shot a Carbon Fiber wrapped barrel before today.

The only points of reference I have are those YouTube videos I watched of guys rattling off thirty round magazine full's in under a minute. Their measured temperatures only went into the 150s even after that. It wasn't until the third or fourth magazine full that they started to climb into the 200 degree mark.

So, what am I to deduce from this particular range session shooting my DIY Carbon Fiber wrapped rifle barrel??? Right now I'm inclined to call it a cold weather success because I got no signs of delamination, weakening or deformity from the Carbon Fiber Tube itself. In fact, only if I put my hand on the metal parts at the muzzle and the chamber end could I feel anything resembling high heat.

Again; If I was running this test during the Arizona summer I may have gotten a different outcome. I'm going to keep the barrel in place until then and make a few more treks to the shooting range in the upcoming weeks just to confirm that this wasn't a weather related fluke.

Those 45 grain soft points showed signs of real promise when I shot those latter rounds. The fifty grainers also gave me some MOA groups so I'm not ruling those out either. They just need a bit more work. Next time I'll take my chronograph so I can get some velocity readings. I also want to see if I get any points-of-impact changes when I put my suppressor on.

This is an addition to what I've already described above. I thought of this after I'd already posted this comment. As crazy as this may sound, I'm thinking about next time I'll also take along a Kitchen-Thermometer so that I can slip it into the bore at the muzzle and the chamber end. Hopefully it won't explode inside my bore. They a appear to be rated up to 520 degrees and the probe looks like it's a small enough diameter but I'll have to do some checking before I actually do this.

I'll be back.

HollowPoint

I'll upload those pics and those short clips of video once I get them edited down.

[HollowPoint]

I'm still working on those video clips. I got one of them edited down to an uploadable size but the other two; the ones I took with the FTS Tactacam camera came out so washed out at the center of the image that I can't repair them with the video editing software I have to work with.

I was in the shade filming through the scope at a target that was reflecting sunlight right back at the Tactacam camera and the inbedded software adjustmenets that came with this camera are so rudimentary that there was no adjustment I could make that would make these video clips any more visible.

I haven't given up on them just yet. I have another video editing software that I downloaded some time ago that has many more editing features but I'm going to have to learn how to use that software before I can use it to try to fix these washed out video clips.

The photos I took of the two targets from this same range session came out a whole lot clearer. That's because I used my SLR camera to photograph them. You can find those below. I tried to include explanitory text along with the photos so I hope they don't end up being more confusing that clarifying.

I went to the range with a batch of 55 grain Dog-Town fire-forming loads on top of some 3031 powder that were still in the shape of common 223 remington brass. I also had 25 rounds of previously fire-formed 50 grain soft points and 20 rounds of 45 grain soft points that were loaded with varying charge weights of Benchmark powder.

As I already mentioned in my previous post, the 45 grain soft points showed great promise and the 50 grain soft points gave me a couple of MOA groups but nothing any tighter than that. I was just happy to get what I got out of them; and extremely happy that my Carbon Fiber wrapped barrel ended this testing session none the worse for wear. I did have to shoot most of my ammo before finally setting down to where I was then able to get some decent accuracy.

I still have a bit more editing to do before I upload any of this stuff onto my Instagram account but for now, here are those target photos.

HollowPoint

[HollowPoint]

I contacted Rylan over at RockWest Composites shortly after I'd finished my initial range tests the other day. He had asked me to let him know how my initial testing went once I was able to get to the range. All I did was send him a copy of the same of text I posted in my previous update here on this thread topic. I finally got a reply from him today.

The time before last I corresponded with him I had asked about the possibility of them making Carbon Fiber tubes using epoxy resin that was able to withstand higher temperatures than the CF tube I was using now, which was rated as being able to withstand up to 250 degrees Fahrenheit. At the time he mentioned that he would be talking to his engineers in an upcoming meeting about possibly coming up with a Carbon Fiber tube using just such a resin.

This time when he replied to my email he mentioned that they were making progress in that direction and he asked me to contact him again in a couple of weeks. He should have some more information about the new CF tubing they're working on putting together. I think it's a situation where they have to tool up for a different type of tube wrapping. I don't really know at this point. I'll just have to wait and see what he has to say next time I email him.

I finally got that short video clip uploaded to my Instagram account. It includes some hastily uploaded photos that include some of the same ones you've already seen. For some reason the audio in that video clip I uploaded didn't come through; just the video alone. Another thing was that I was in such a hurry to upload them that I forgot to scale down my images so now only the centers of the photos are visible. This cut the edges off some of the pics including some of the text that extended to the outside edges of these same photos. Oh well. I'm still learning how to upload stuff that contains multiple pages in one uploading session. I'll know better next time.

I fully intended to take down the previous upload but it got a fair amount of attention; I mean more than my obscure Instagram account is used to getting so, I left it up.

https://www.instagram.com/p/B8aXpNCBV6A/

I've already loaded up my next batch of cartridges for my next trip to the range. It may not be for another week cause I got taxes scheduled and annual medical checkups and a couple of other things I have to get finished up first. Also; I discovered that I've had to tweak the magazine follower on my rifle magazine in order to cycle my cartridges reliably. I had no problem cycling the 223 Ackley cartridges in my previous spiral-fluted barrel but this new Carbon Fiber wrapped barrel is a bit more finicky. I 3D printed a couple of new magazine followers and finally got one to work on the factory magazine. Now I have to make one up for my DIY 3D printed extended magazine as well.

I'll be back with updates.

HollowPoint

[HollowPoint]

I touched on this in my previous post. It has nothing to do with the DIY Carbon Fiber barrel itself but it does have to do with going from 223 Remington chamber to a 223 AI chamber.

With my last re-barreling/re-Chambering of this same rifle to 223 AI I experienced no issues with reliable feeding or cycling of cartridges from the magazine to the chamber. This time around however I did notice that I'd be humming right along and them one out of three or four attempts at chambering another round would result in the points of my bullets coming to a dead stop as they hit the face of the chamber end of my barrel just below the actual chamber opening.

I 3D printed a few different configurations of the factory magazine follower until I hit on the right shape that would allow for reliable cycling/feeding of fresh rounds into the chamber. My DIY 3D printed Extended Magazine required a bit more work to get it to feed reliably. With both magazines I needed for the loaded rounds to have more of an upward tilt at the tip of the bullet/cartridge. With the factory mag it was just a simple case of modifying the shape of the follower. With my 3D printed DIY mag I had to not only print out a differently shaped magazine follower, I had to also fabricate a metal liner for the magazine in order to be able to have the loaded rounds sit ever so slightly higher in the mag in addition to having the loaded rounds be tilted upward enough to funnel into the chamber without hitting just below the chamber opening.

I finally got it all ironed out so now I'm just waiting for my next opportunity to get to the shooting range again for testing session number two. By the way, that new Kitchen-Thermometer I ordered showed up yesterday. When I opened up the box to take a look at it I could have kicked myself for not buying this instead of that laser thermometer in the first place. The probe on this new thermometer will fit nicely and deeply right into the bore and the chamber for what I hope will be more reliable temperature measurements. I didn't mention this before but I had actually contemplated taking along to the range a rectal-thermometer and shoving that sucker up into the bore in hopes of getting more accurate readings. Common sense and fear of having that rectal-thermometer explode inside my bore won over. I bought the Kitchen-Thermometer in stead.

Here's the Kitchen-Thermometer I'm referring to.
https://www.ebay.com/itm/Meat-Thermometer-Probe-Digital-Grill-Instant-Read-Food-Cooking-Grill-Kitchen/124076293179?_trkparms=aid%3D555018%26algo%3DPL.SI M%26ao%3D1%26asc%3D225074%26meid%3D286ab1985847497 98517908ae553156b%26pid%3D100012%26rk%3D2%26rkt%3D 12%26sd%3D401747922155%26itm%3D124076293179%26pmt% 3D1%26noa%3D0%26pg%3D2047675&_trksid=p2047675.c100012.m1985


Here too is a photo of what I was attempting to describe about my magazine feeding issues and fixes.

HollowPoint

[HollowPoint]

It looks like I'll have another chance to get to the shooting range again next week some time. I've been chomping at the bit to get back out there to do some more testing.

While I've been waiting for that opportunity I've spent a little time Tweaking my 3D printed Extended Magazine models so as to get them to work with both the 223 Remington configuration cartridges and the 223 Ackley Improved cartridges. When I modified my existing DIY Magazine by using a metal insert to facilitate reliable cycling, although it did make it work reliably, it also made it alot heavier too. I figured that an all ABS-plastic mag would be much lighter. I had to print out a total of three magazines before I finally got the dimensions just right so they feed reliably. I know that doesn't sound like much but when you figure that each magazine takes eleven and a half hours to print (not including the base-plate, the follower and the spring-follower, that's alot of printing hours. But, I just started each print at about 7:30 or eight-O-clock at night and they were ready when I woke up the next morning.

The magazine design was originally meant to hold 9 rounds but all I had on hand was some .055" Music-Wire which was a bit on the thick side for this application. I had run out of the .047" Music-Wire and my local hardware store was out of the thinner wire as well so my magazines will only accept a total of 8 rounds; and even then I have to cram that 8th round into the magazine. I don't really like doing that because I feel like I'm crushing to spring to much. For now I'm only loading seven rounds into them. Once I get my hands on some more .047" spring-wire I'll make up a new set of springs so I can load the full nine rounds into these DIY Extended magazines.

I uploaded my only image of these 3D printed magazines onto my Instagram account; along with a short video clip showing that they actually work. The link is as follows:


https://youtu.be/Jw-9KSglaPY

I'll be back with updates when I've had a chance to finish up that second round of testing.

HollowPoint

[HollowPoint]

I got a chance to conduct my second round of range tests on my DIY Carbon Fiber Barrel this morning. I'm going to start out with the Frustrating news first and try to work my way toward some sense of happiness and accomplishment.

Have you ever gone hunting or to the shooting range or on a fishing trip in anticipation of good things, only to find out you had forgotten your fishing rod or your tackle box; or your bullets or your hunting license? I had set everything I planned to take with me to the range right by the back door so I wouldn't forget any of it. This time around it was that new Kitchen Thermometer that I had purchased just so I could get more precise temperature readings by sticking the probe of that thermometer into the bore of my Carbon Fiber wrapped barrel rather than trying to take temperature readings on the outside surface of the barrel. I did still have the laser thermometer in my range bag but that thermometer was just not giving me accurate readings.

Another frustration was that I had been hoping to get my DIY Film-Through-My-Rifle-Scope attachment finished by now so that I could document these things I'm sharing with you here. With the internet being rife with liars and exaggerators I wanted to be able to show you, not just tell you how things went for me this time out. My existing TactaCam camera with it's FTS attachement has failed each time out to give me anything I would consider to be decent footage of my outings. ( an expensive P-O-S) With my DIY attachment I believe I'll be able to get far clearer documentation when I attempt to film through my scope. These were the frustrations I faced on this morning's shooting range outing.

The bad news had to do with the 4-inch shifts of my Points of Impact on target when I put my suppressor on. Granted, I got the same results when this same rifle was in it's factory configuration with a 22" pencil thin barrel but, I was really hoping that with the larger diameter of the barrel as it was now at only 18" long and with the Carbon Fiber tube in place it would have displayed a bit more rigidity than with it's skinny factory barrel on. With the factory barrel on this rifle my points of impact only dropped about two-and-a-half inches and a bit to the right. This morning when I aimed for the center of the bullseyes my bullets were hitting 4" low; both the 45 grain soft points and the 50 grain soft points.

In addition to these lower impact points I found that my groups opened up from the MOA and Sub-MOA groups I got before with my 50 Grain loads and the 45 Grain loads respectively. That surprised me because usually when I've mounted my suppressor it tended to tighten my groups just a bit. Not this time. They were still in five shot clusters of about an inch and a quarter or so with a pesky flyer that would open the group up a bit more but they were no longer MOA or Sub-MOA groups. My suppressor is a stainless steel mono-core baffle design with a titanium outer tube so it is on the heavy side but still, 4" was a bit much in my opinion.

The Good News? I loaded up 15 fresh rounds in the same 45 and 50 grain soft points I went out with in my first testing session. I started with the charge weights that showed the most promise in my previous outing. I got pretty close to the same group sizes with the promising loads so that was a good sign. It showed me that the first outing may not have been a fluke. At five rounds for each charge weights I loaded the promising loads and then two more charge weights that I increased by .3 grain increments. I should tell you here that I've been using load data for the 223 Remington to work up loads for this 223 Ackley improved so I felt safe increasing the charge weights by a bit over the 223 Remington maximum charge weights; and in point of fact I got no pressure signs with any of my loads.

With the 45 grain soft points at the same promising charge weight of 27.6 grains I managed to pull off another Sub-MOA group. I also got a Sub-MOA group with this same bullet and 27.3 grains so I think that this may be a sweet spot. Incidentally, one of the pieces of equipment that I didn't forget to take with me was my barrel mounted chronograph. At 27.3 grains of Benchmark powder I was getting an average of 3338 FPS and with the 27.6 grain charge weight I got an average of 3346 FPS. I also fired five rounds with a charge weight of 27.9 grains of Benchmark powder but my group opened up to four within an inch and a flyer that opened the group up to a good two inches. It turns out that my concerns about going to a shorter barrel and loosing some velocity may have been unfounded. For me this is good news.

The 50 grain soft points on top of Benchmark powder Still managed to give me a couple of MOA groups similar to my last outing's results so, here too I'm thinking that this DIY Carbon Fiber wrapped barrel is holding it's points of impact as long as I hold my aim as steady as I can.

At 26.5 grains of powder I was getting an average velocity of 3170 FPS from that 18" Carbon Fiber barrel. At 26.8 grains of powder I got an average of 3200 FPS. 26.8 grains was one of the promising loads from my previous trip to the range. It gave me similar results. I say "Similar" only because I managed to screw it up by shooting a flyer that opened up an otherwise promising repeat of the last group I shot with this particular load. It opened the group up to about 1 1/4". At 27.1 grains I got an average velocity of 3230 FPS with the 50 grain soft points; and this was my tightest group yet with the 50 grainers. It measured just under an inch at a hundred yards.

These groups and velocities were all good news for me. So long as I didn't mount the suppressor my groups seemed to fall in line with my previous range testing groups. Further good news was the fact that the Carbon Fiber tube itself showed no ill effects from this range session either; and this time around I really did fire with less of an eye for keeping the barrel as cool as possible. Each five round charge weight was fired in under a minute; give or take a few second here and there. I put my laser thermometer on my suppressor at one point and I got a temperature reading of 172 degree Fahrenheit. At the same time, readings on the barrel itself were only registering no more than 76 degrees Fahrenheit. I knew these readings weren't even close to reality. Oh well, I plan on doing one more range test then I'm calling this project completed. I'm also calling it a success. I would still much prefer a Carbon Fiber tube with more heat resistance though. Something along the lines of maybe 400 degrees Fahrenheit of heat resistance. I can't help but think that with more heat resistance perhaps my points of impact would not have dropped by four inches. I don't know if this line of reasoning is correct or not but it just sticks in my mind. The higher the heat resistance of the Carbon Fiber composite the better, I think.

I did take my Cheap action cam camera with me and I did get some sporadic and short video shots. I also got some still photographs of my groups but I have yet to edit them down to a small enough file size so I can upload them to my Instagram account or my YouTube account. I'll try to get that done this weekend some time.

I believe that one more range session is in order. I want to make sure that my previous two sessions were not a psychological or placebo-type of anomally. I can say with complete confidence now that my DIY Carbon Fiber Wrapped barrel project is really a viable choice for anyone who would like a Carbon Fiber wrapped barrel but have shied away from them because of the price. If you have a metal lathe and the know-how to use it, this may be a doable alternative for you. Even better still would be to just save up your nickels and dimes for as long as it takes and just buy one premade. Nothing wrong with that.

I'll be back with those pics I mentioned a little later. Thanks for sticking around everyone.

HollowPoint

[HollowPoint]

Here are a couple of closeup photos of the two targets I attempted to describe in my previous post. In them you can see how my impact points shifted 4 inches lower when I mounted my suppressor on the DIY Carbon Fiber barrel.

The target with the word "Suppressor" penciled in at the top center is there to draw your attention to the two holes at the top center of the target. Those two hole were made when I fired the fifty-grain pills at an identical target that was sitting just above the target with the low impact holes.

I got the same drop distance with both the 45 and 50 grain bullets.

The second photo is of my groups shooting both bullet weights. The 45 grain bullets along the top row and the 50 grain bullets along the bottom row. Except for those groups shot with my suppressor mounted, all other groups generally impacted in the same way as my previous shooting range outing.

The short video clips I mentioned that I took will take me a bit longer to edit down the file size on. I'm hoping to get those up within the next few days.

HollowPoint

[HollowPoint]

I got my next batch of ammo all loaded up. I'll be testing to confirm my previous sub-MOA loads were/are the real deal. I found in that last testing session that My Carbon Fiber barrel seemed to be holding up well with the slightly faster back to back firing of my load workup loads.

This time around I've made sure to bring along both my thermometers; the laser thermometer and the newer kitchen-thermometer. I'm really hoping to get some more accurate temperature readings with that kitchen-thermometer. I'm looking at sometime next week for my next foray to the range. The timing is good cause the weather here in Arizona is starting to get a bit warmer compared to the last two times I went out. I'm curious to see if the warmer ambient temperatures will translate to a hotter barrel.

Another thing too is the fact that I finally got my 3D printed SmartPhone scope mounts done. I've tested them on my air guns in the back yard and they seem to work just fine but, my air guns have no recoil to speak of so I have yet to see how these 3D printed scope attachments hold up to the recoil of a 223. They should be alright but I won't know for sure till I try them.

I figure that documented video proof is probably better than me just making written claims about the suitability of the type of Carbon Fiber tubes I've used for this DIY Carbon Fiber Barrel project. The same goes for my claims of accuracy and my marksmanship. (or lack thereof)

Anyway, I thought you all might like to see what I was talking about with respect to that 3D Printed scope mount setup for my smartphones. I happen to have three old no longer in service smart phones so I made some dedicated adapters for each model. One Android phone, one iPhone 5s and an old HTC smart phone. All came with on board video cameras so I thought I'd put them to use. The HTC cell phone adapter is not yet printed cause I ran out of print filament. I ordered some more so once it gets here I'll print out that last adapter.

One other thing I should mention about my 3D printed smartphone scope mounts is that I made one as a side mount unit that allows me to still be able to sight through the scope in typical fashion and the other is made to sit on the back end of my scopes and sight via the live feed of the cell phone's video camera. The main bodies of my scope attachments are sized to be able to use the same plastic sleeves that came with my Tactacam Camera's FTS unit. I could have printed my own but since I already had these factory made Tactacam sleeves I just used those instead.

Here is my CAD rendering of the 3D printed units I've already printed out. I'll be back once I've finished up that last range session.

HollowPoint

[HollowPoint]

I got rained out the week following my last post. It rained all week in my area. The week after that on the days that I had free to go to the range I got rained out again too.

Now this week I'm being urged to stick close to home due to those viral-scare reasons that by now most are aware of. I'm not the one who's scared but for the sake of some in my family I've consented to stay close to home for now. Crazy times we're living in. Like I said; I'm not scared for myself but our mass media has done a stellar job of striking fear where common sense once used to be.

I'm just posting this to let those of you who were following my progress know that I'm still hear and this project is still on. I'm just waiting for an opportune opportunity to get to the range for my final testing session. Stay safe everyone and fear not.

HollowPoint

[HollowPoint]

I finally got a chance to get to the shooting range today after being rained out twice and then being Corona'd into staying put for a time.

It amazes me how psychotic some people have gotten over this virus thing. Even on the shooting range it was a completely different atmosphere. I guess I'm lucky cause my life really hasn't been altered to much other than having to deal with scared people.

All of that aside, I'm happy to report that my Carbon Fiber Barrel project is still holding it's previous accuracy potential. I got the same or similar points of impact. I got several MOA groups and I would have gotten the same or similar sub-MOA groups if my marksman wasn't so inconsistent. I've had very little range time or trigger time lately.

With nearly every five shot group I sent down range I managed to pull flyers. I knew they were going to fly away from the group the moment I squeezed the trigger; I just knew it. I'd get a ragged hole group started then I'd pull the next shot or the next two shots.

My excuse for these flyers is the lighter weight of my rifle now that it wears the lighter Carbon Fiber wrapped barrel. Yea, I'm sure that if I still had my heavy spiral fluted bull barrel on I'd still be able to come up with an excuse for my lousy shooting technique but still, I'm happy with the overall results I got all three time I've been at the shooting range. An accurate rifle is what I was hoping for with this project. It's to bad my marksmanship couldn't have equaled the accuracy potential of this Home-Smithed Tikka T3 light.

This time out the 50 grain soft points were wanting to give me ragged hole groups before I screwed them up with flyers. The 45 grain soft points were still giving me MOA groups but just barely.

I also loaded up some of the 55 grain Dog-Town bullets I bought a few years back but they didn't do well at all.

Next time I'm out shooting it will be to hunt coyotes. Now that I know what this Carbon Fiber barrel can do I'm confident that if I get a clear shot at a coyote I'll be able to put him down out to three hundred yards with the fifty-grain pills.

I did take some photos and some video but I have yet to edit those video clips. I'll try to get them done by the end of the week and post them with my final thoughts.

I'm seriously thinking about re-doing my Tikka Hunter rifle now. I rebarreled that particular rifle about a year and a half ago and it too was made nose heavy by that re-barreling job. If I can get the components together over the summer I may just go ahead and lighten that rifle up with another home-smithed Carbon Fiber wrapped barrel.

I know how to do it now; and I know it will work.

Incidentally, I took that long-nosed kitchen thermometer with me to the range today. I could'nt figure out why it was giving me such low numbers. Both at the muzzle and at the chamber end it was reading in the high 30s and low to mid 40 degrees. (ambient temps were 67-68 degrees) I thought that this themometer too was just a useless piece of excrement like the digital thermometer I had used prevously. Then I realized I had it set for Celsius instead of Fahrenheit. What an idiot.

Anyway, I wasn't exactly taking it easy on the barrel. I was shooting my loaded cartridges five rounds a session in under a minute and then as soon as I reloaded the magazine I did the same with very little time for the barrel to cool. The thermometer never read more than 140 to 142 degrees Fahrenheit. I'm thinking it had to have gotten a bit hotter than that but even then it never reached the stated 250 degree tolerance level of the Carbon Fiber composite tube I used in this project.

I'm not to concerned about what anyone thinks about my Carbon Fiber wrapped barrel project at this point. I'm calling it a success. My points of impact have remained the same or nearly the same over about 90 rounds of different weights from 45, 50 and 55 grains. It was only my marksmanship or lack thereof that has caused variations. I'll be back after I've had a chance to edit those video clips.

For those of you who have been following this thread, Thanks for sticking around this long. Sorry it took so long to get this final range session done.

One last thing I want to mention to any of you Arizona shooters. I just found out this morning at the shooting range that they raised the price of shooting at that range from ten bucks to fifteen bucks so now this hobby just got a bit more expensive. I don't know if this only applies to the Usery Pass shooting range or if it applies to all shooting ranges across the state. Just thought I'd let you know. That price hike to effect today.

HollowPoint

[HollowPoint]

I thought I'd upload a pic of the latest targets I shot during my last time out to the shooting range. At first glance they don't look very impressive but when you consider that I was there to test the effects of a more rapid shooting pace to see how the heat generated would affect my home made Carbon Fiber barrel, I'd say the barrel and the Carbon Fiber tube it wears passed with flying colors.

What impressed me the most was that I got very similar groups, points of impact and velocities when compared to the last two times I did these range tests. I only wish I had taken my time between shots. This may have mitigated alot of the ugly flyers I was getting. No matter now.

As I mentioned before, the three topmost bullseyes of the top page were shot with the 45 grain Speer Soft-Points. I kept the charge weights the same as the charge weights from the last two range sessions that gave me the best results. Except for the last five rounds, which I had increased the charge weights of, those five rounds threw my point of impact farther to the left and made them more disbursed.

The lower two bullseyes of the top page and the upper left bullseye of the lower page were shot with the Speer 50 grain Soft-Points. Here I started out with very tight clusters only to be opened up by my inability to hold steady enough. I should have taken my mechanical rest with the remote trigger. Then I might have been able to take my human error out of the equation but I just didn't think of doing that at the time. Maybe then I could have stacked those 50 grainers one on top of another at a hundred yards. Oh well, maybe next time.

The three lower-most bullseyes of the bottom page were shot with the 55 grain Dog-Town bullets I got from MidwayUSA several years ago. I still have a bunch on the shelf so I thought I'd try them to see if they would shoot for me. Those 55 grainers weren't quite as cooperative as the lighter Soft-Points. I've basically been using them for fireforming my 223 Remington brass to 223 AI brass.

I hope to go coyote hunting within the next couple of weeks. I think I've proven to myself everything I needed to know regarding my home made Carbon Fiber wrapped barrel project. I still have to edit those short video clips I took during this range session. It's just three 3-minute clips but it's a total of nine minutes of footage I have to whittle it down to one minute in order to upload it to my Instagram page. I can make it a bit longer for my YouTube page but it takes my antiquated computer equipment a long time to upload even a five or six minute snippet of video.

I'll be back when I get that done.

HollowPoint

[HollowPoint]

I make my videos on antiquated computer equipment. It takes me two to three hours to edit them. Then I have to wait about a half hour to fourty-five minutes more for my computer to struggle through the file saving process. Then I have to wait another half hour for this same Windows-7 laptop computer to convert the movie from a Windows Movie Maker file to an MP4 file so I can upload it to my YouTube account.

All of my videos are short, choppy and poorly made but they're good enough to show that my projects eventually end up successful; if I don't give up on them.

Here's my short choppy video of the last range testing session of the DIY Carbon Fiber wrapped rifle barrel that is the topic of this long winded thread.

I hope to be doing one more of these DIY Carbon Fiber wrapped rifle barrels before the summer is over. Now that I know how to do them it shouldn't take me nearly as long.

I know I said in my previous post that this would most likely be my last comment on this thread but, I want to take this same Tikka rifle out on a coyote hunt. If I have a successful hunt I may resurrect this thread just to show off a bit; then I can call that post, "The last post."

I think this topic of Carbon Fiber wrapped rifle barrels might have gotten a bit more interest if I had posted it on the "Special Projects" section of this forum but at the time I started it I thought it had more to do with gunsmithing than anything else. I did attempt to contact the powers that be here via an email to ask if they could move this thread over to the "Special Projects" section but I never got a response and I just didn't do any followup on it.

Thanks alot for sticking around everyone.

HollowPoint


https://youtu.be/cD4huqlSc2k