Hansol's Slug Gun Part II

[hansol]

Hey guys,

I apologize for pulling the original post. I was supposed to get out to the range today, but the weather turned crappy. So to kill some time, I decided to re-write up my slug gun post from the other day.

As most of you know by now, I wanted to come up a way to shoot copper slugs out of my SxS 12 gauge. I had heard a lot about shooting hard cast lead, but I figured a copper jacket might make things even better penetration-wise. So I set out to try this out.

Long story short, I came up with using 1/2" copper pipe caps filled with melted lead as a slug. They mic out at about .702", and then you wrap them with masking tape to bring them up to .729" (You can use teflon or paper for this to, a'la paper patching, but I'm lazy and masking tape is faster). In the end these slugs weigh around 580 grains. I called them "Hansol Slugs". Very original.

Secondly I had to come up with load data to shoot one of these. A lot of this was based on opinions and experience from other slug shooters, as well as a heck of a lot of cross-referencing. The rule of thumb for slugs is that a comparable weight shot load will generate more pressures than a comparable weight slug load. That's a fancy way of saying slugs generate LESS pressure than shot. So with that in mind, I developed the following loads:

*Now bear in mind, these are unpublished, untested loads worked in MY gun, and my gun only so far. I don't recommend others use them until they are pressure tested.*

Black Powder Load
-Win 2 3/4" Hull
-CCI 209 Primer
-105 grains Pyrdodex RS
-Fiber Wad
-580 grain Hansol Slug
-roll crimp

In theory, this load is going 1250fps. Approx pressure estimate = 6500psi. Actual pressures and speeds are unknown

Smokeless Load
-Federal 3" paper base wad hull
-CCI 209 Primer
-42 Grains Blue Dot
-WAA 12 white wad (petals cut off)
-580 Grain Hansol Slug
-roll crimp.

In theory, this load is going 1400fps. Approx pressure estimate = 9500psi. Actual speed and pressure are unknown

Again, these are untested loads, based on a lot of theory, and I'm not sure how safe they are at this point. Use at your own risk. Most importantly, DON'T USE IN A GUN WITH CHOKES. I'm pretty sure that would cause a LOT of problems. No chokes!

Range Day.

Here are pics from my range day the other week.

Here's my slug gun, a Lanber Supreme with 3" chambers. She has express sights, and barrels cut to 24". She's very much a "modern" gun:
http://i129.photobucket.com/albums/p204/hansol04/DSC00082.jpg

This was 35 yards:
http://i129.photobucket.com/albums/p204/hansol04/100_0874.jpg

Guess which holes are mine:
http://i129.photobucket.com/albums/p204/hansol04/100_0877.jpg

As a "penetration test" on the day, I shot my slugs at a 1/2 steel plate. This happened EVERY time I pulled the trigger:
http://i129.photobucket.com/albums/p204/hansol04/100_0884.jpg

Ten Yards (the ones on the left were test rounds):
http://i129.photobucket.com/albums/p204/hansol04/100_0880.jpg

Test target @ Ten Yards. 4 Rounds. The ones on the left are left barrel, ones on the right, right barrel. I actually used proper aiming procedures this time instead of just banging away:
http://i129.photobucket.com/albums/p204/hansol04/100_0881.jpg

[hansol]

Here are some pics of the slugs, wrapped and unwrapped (the one on the right is a reject, as you can probably tell from the base):

http://i129.photobucket.com/albums/p204/hansol04/100_0887.jpg

http://i129.photobucket.com/albums/p204/hansol04/100_0888.jpg

[hansol]

Theory.

Here's a little bit of theory behind my rig. Basically my idea was to come up with a "stopping" gun. And while I didn't have anything against hard lead slugs, I just thought a copper one might work just as well, if not better. It turns out that this idea of a 12 gauge stopping gun is actually 140 years old, and goes back to the old British 12 bores of Africa. These guns tended to fire (in a 12 bore) a 600 grain round ball at around 1100fps. So this idea isn't an original one.

Secondly, a lot of guys were wondering about pulling a slug load out of "thin air". Well it wasn't quite that easy. I literally spent days reading old load data, querying experienced shooters, and reading books by WW Greener, Sam Baker, and all those old boys, trying to get an idea on loads and pressures. So the following is a comparison, showing my logic and reason:

(And I should give credit where it's due: a couple of the members here on the forum helped me greatly with this analysis, and I very much appreciate it. You know who you are, so thank you.)

Approved Load
-Federal 3" Paper base hull ---> Low pressure hull
-Fed 209a Primer ---> Hot (hottest) primer ---> High Pressure
-38 grains Blue Dot
- WAA12 white wad ---> Low pressure wad
-1 3/8oz lead shot ---> High pressure (compared to slug)

This generates 8800psi, and 1300fps

My load
-Federal 3" paper base hull ---> low pressure hull
-CCI 209 Primer ---> low pressure primer
-42 grains blue dot
-WAA 12 wad ---> low pressure wad
-580 grain Hansol Slug ---> My slug is 1 1/3oz, so is lighter. Plus, it's a slug, so using the rule that a slug gerates less pressure than shot ---> Low pressure

As for black powder loads, I came across the following stats in the Dangerous Game Journal, based on a 12 bore shooting a 600 grain round ball using black powder:

82 grains powder = 5350psi
110 = 6850
137 = 7800
164 = 9650
191 = 9750
220 = 11400.

I can't find any sources to verify the above black powder loads in a shotgun with charges higher than 105 grains, so haven't tested any higher loads. I don't like relying on just one piece of data. So I wouldn't recommend anyone basing their loads on the above stats until you can get something to cross reference.

[anachronism]

Just a thought, you might be able to make yourself a mandrel & flare the open end of the copper cap a little closer to your bore diameter. This could eliminate the need for the tape. Or you may be able to step the back 1/2 instead of simply flaring it. Lots of possibilities here.

[hansol]

That would actually be a really good idea, and would certainly speed the process of making these things. The taping is what really slows things up.

I guess I need to track down a steel rod or such that is .723 in diameter now (allowing for .003" sidewall thickness). Expanding the caps will probably increase the finished slug weight, but probably not enough to warrant much though.

[anachronism]

A machine shop could probably make you one pretty cheap. If you're concerned about choke interference, you could experiment with only filling the cap up 3/4 of the way or so. The unfilled skirt should compress in the coke. It would sort of end up like a minie ball.

[hansol]

Well, seeing as my gun has no chokes, I don't think I need to worry about that lol. But that being said, I wouldn't recommend anyone shoot these slugs in anything rig with chokes installed. That would just be screaming for trouble.

[Heavy lead]

Wow, what a good idea, and talk about a short range defense slug, holy cow, or as far as that goes, you could shoot them backwards and go through anything. Question to you sand and flux (solder flux) the pipe cap before you pour the lead so it is bonded?

[missionary5155]

Good evening Hansol
Loks good to me.
I am not real sure just belling one is going to help. I think you will be inviting the slug to tip unless you can get at least 3/4 of the bearing length to bore size. But it would be a simple swag tool to make.
AAAANd if anyone does not like your experimenting with a neet idea and wants to start a spitting match... send them on down. I know a couple LLamas that will face off with anyone.
Mike in Peru

[hansol]

Hey guys,

Firstly, no I didn't flux the insides of the caps, but I think for this next batch I will do that. It seems like the lead cores don't "stick" as well as I'd like them to; they don't fall out, but you can feel that they are a little loose. A quick hit with a hammer squished the lead enough to make a tight fit, but I think fluxing the cap would work better, and would keep the slug together better on impact.

Secondly, the way I have been firing the slugs has been as a "solid", ie. the hard copper end being the end that impacts the target, instead of the soft lead "open" end. I haven't fired any yet as a "soft point", so can't comment on how they react.

Mike, I will certainly send them down to face off on your bad-ass llamas. I just won't let those guys in on the fun experiments anymore I suppose. Guns are "dangerous", don't you know, and the safety police need you to know that... Silly buggers.

[peterthevet]

Very interesting post!! Thankyou for reposting your idea/load data/results - this has a lot of potential. I initially read your post and later when I went to study it again it was gone....arrrgghhh!! This time I made myself a paper copy for future reference !! There is a lot of great info on this site...thanks again.

[anachronism]

Now I wonder how it would work the swage down a larger cap to bore diameter instead of flaring. I'm sure 3/4 caps could work in this manner, especially if they are annealed before swaging. All it would really require is a hole in a thick piece of steel, starting at the nominal 3/4 or so diameter, tapering to .72 or so at the end. The only other thing required would be a punch slightly smaller in diameter than the ID of the cap at it's finished diameter. This is getting interesting.

[briang]

The three quarter caps are three quarter ID. hansol said the half inch caps where .702 OD so if the material thickness is the same that would make the three quarter .952 OD:shock: That's a lot to swag down to bore size.

[hansol]

Well what I was thinking was maybe finding a .723 diameter tapered rod, and driving that the whole way into the cap, thus expanding the diameter + sidewalls to an overall .729" outside diameter. That being said, there is a lot of options here. I've also seen swaging tools for making bullets out of copper pipe, so I think swaging is an option as well. Now I just need the money for all these toys.

But again guys, remember I haven't pressure tested these loads, I have no idea how safe they are (mostly regarding the smokeless load), I THINK they are within proper parameters, but can't confirm that. Thus I don't recommend anyone try these until more testing is done. I'm not trying to be a downer, just want to make sure everyone knows what the risks are.

And again, I apologize for not getting out to the range this weekend. It snowed like crazy up here, so wasn't worth it. I should be out this upcoming weekend though, and will be able to post a few velocities. I'm also working on a heavier black powder charge, so will post those results as well. Cheers.

[anachronism]

The three quarter caps are three quarter ID. hansol said the half inch caps where .702 OD so if the material thickness is the same that would make the three quarter .952 OD:shock: That's a lot to swag down to bore size.

Probably. That's why I need to go to the hardware store with my calipers. I imagine different cap manufacturers will have different wall thicknesses, too.

[hansol]

Well as most everyone has come to the conclusion that I am insane, I figured I'd go with the general consensus and post this and get feedback:

I think I've come up with a way to test the barrel pressures my slug creates. Yes, it will take a crazy person to try it, and one must be willing to blow up/ruin a shotgun to test if the rig works, but I don't really have a problem with that, as most of you know by now.

My theory is actually based on flintlocks, and their touch holes. "Modern" flintlocks, from what I can tell, operate at higher pressures compared to a shotgun due to a number of things: Rifling, smaller bore diameter, powder charges, etc. And the brilliant thing is that these flintlock rifle barrels have essentially a hole drilled through the chamber. Even more brilliant (and condusive to this exercise) is that gas shoots out this hole when the cartridge is touched off. I think that if a guy were to somehow measure these escaping gases and compare them against a constant, one would come up with a measureable way to show pressures.

My idea is to take a shotgun, and drill out a small hole in the chamber. Then tap this hole for a standard touchole liner (I don't know if this is necessary, but it will allow for longevity vs. a standard hole.) Then on top of this hole, one would silver solder a threaded female fitting to the barrel around the touchole that coincides with the male threads of a standard industrial pressure gauge.

Granted, the escaping gases would probably only be 1/10th of the volume escaping from the bore when the shotgun is fired, but I think if a guy fires standard loads that have published data available for them, and uses those as a standard, the related "pressure" indication on the industrial pressure gauge would be your "constant". In the same fashion, if a guy could come across an established recipe for a 12 gauge proof load, the resulting number on your pressure gauge would be a "danger max" for any load tested.

So with that in mind, I need to find myself a donor shotgun. I will be pinching pennies to purchase a NEF Pardner 12 gauge smooth bore, as well as obtain the proper gauges and fittings.

In my opinion, this method is no different than the "crusher" methods for testing CUP and LUP. Only in this case, rather than a crusher/piston assembly, a guy substitutes a pressure gauge instead. I admit though, I don't know if the gases escaping will be at a full 10000psi, or a fraction of that based on hole diameter. I will research this matter more in the coming days.

Yes, I understand I am crazy for trying this, and it is most certainly "unsafe" in some peoples' minds, but oh well. We've already established I'm nuts, and am more than willing to use a string and tire to test things out. At the worst, I bulge a barrel and am out $179. At the best, I have a pressure testing rig to test all my loads.

Cheers.

*note: I don't recommend anyone else try this. It's not a good idea to drill a hole in a chamber of any firearm, ever. It's dangerous, and one could get seriously hurt if they try this. Again, I don't recommend anyone else tries this until I have trialed it and can post results*

[blysmelter]

You will need som kind of one-way-valve between your barrel and gauge, the pressure impulse is so short you will not be able to read the gauge without it.

[hansol]

blysmelter, I do need one of those "things". I don't know what they are called, but I have seen them on many different gauges, including on a compression tester for cars. I always thought they were an internal part of the gauge though? I don't know enough about gauges to know what they are called, but you are correct, I definitely need one to be able to see the pressure results.

I think often you see one needle that will show "peak pressure", and the other needle denotes "current pressure" or something to that extent.

[briang]

There are gauges available that have a second needle that is pushed by the first. This second needle will stay at the highest point the first needle goes until it is reset.

If it where me I would send some loads to someone with the proper equipment and not even consider trying what you describe. But if you want to do it, go right ahead just be nowhere in the area when that thing goes off.

[hansol]

LOL yes, point taken about being "far away when it goes off". I like to experiment, but even I know what a sketchy exercise looks like.

I would love to get a few loads tested, but unfortunately I don't know of anyone who does this up here in Canada. Plus I think there are difficulties with shipping loaded ammunition. I could give a guy with the proper equipment all the components needed to build one of my "loads", but I worry about how responsible that would make me if the loads damage said person's equipment.

Again, I agree, I would much rather send loads away to get them tested, but I have yet to find leads on who can do this.

[hansol]

Here's a diagram of how a CUP testing device works. Figure maybe it will shed light on my above written descriptions:
http://i129.photobucket.com/albums/p204/hansol04/fir_m05_t10_01_large.jpg

[Pepe Ray]

Obviously your willing to expend considerable resources to this end. Why have you discounted the "strain gage " technology already out there? The Oehler (sp)system is what I had in mind.
Also, I've seen magazine articles delineating the manufacture of "home made " testing equipment. ( I'm gonna begin a search).
Pepe Ray

[hansol]

Actually it's quite the opposite. I have fairly limited resources to chase this idea lol.

NEF shotgun = $200
Pressure Gauge = $20ish dollars.
Labour and machining I can do myself, so that won't cost anything.

And if the rig blows up, it will be one of those fun projects that didn't quite work out the way I wanted it to. Losing a $200 junker shotgun is ok by me in this case.

I think RSI pressure equipment will cost me close to $3000 after taxes and shipping and exchange rates, but I'm fortunate in that I don't have to factor in the cost of a computer at this point.

On the other hand, I could put the money towards someone else doing the tests, but again, I'm a dead end regarding who can do this work.

[missionary5155]

Good afternoon Hansol
Prior to drilling a good barrel you could give the "Case Expansion Measurement" a try.
Get a 3" mag factory load ( the highest presure load you can find) and fire 3 of those in your shotgun.. ONE barrel only. Take Micrometer and measure the FATTEST part of the base area. The 3 shots will give you a good average. That measure ment is your MAX case expansion.
If you stil have your fired cases measure those. This should give you a good idea what YOUR shotgun chamber is willing to safely absorb and expand to.
This is how I do my load developement. Rifle, pistol, and shotgun. Ken Waters published this years ago and I think he has a Good simple method to keep our limbs attached.
It is interesting that as you reach this MAX case expansion measurement the law of "Deminishing Results" has already come into play and adding more powder does not really give much velocity increase. Just lots of pressure.

[hansol]

Hey Mike,

I like that idea, as I could do that test with my current SxS, and do it safely at that.

Question: does factory ammo have the pressures stated on the box? I haven't looked at the boxes that closely before.

And I should repeat that the above "pressure gun" is at this point just an academic exercise, as I don't really know when I will be in a position to build/test it. Neat idea on paper though.

[dubber123]

You can look up SAAMI pressure specs. I believe for 12 ga., 2-3/4 and 3", the SAAMI spec is 11,500 Psi.

[eye shot]

hansol
You could try Precision Reloading--shotshell proof testing--five shot string velocity and pressure average.

[longbow]

Something else I have thought about but not followed up on is to see if a plastigauge strip would fit between the metal head on the hull and chamber wall. These strips should be available in various thicknesses and are compressible to check shell bearing clearance. If they fit, that may be a relatively easy way to check the compression of the strip relative to factory rounds or rounds of known pressure. As the head of the hull expands so the strip compresses then is checked with a micrometer after.

Similar in principle to the crusher idea but no drilling. At worst the back end of the chamber may have to be reamed a thou or two larger to allow a strip in.

Also similar to the case head expansion idea but spring back wouldn't be an issue here.

Just a thought for a poor man's pressure test set up.

Longbow

[briang]

That's a good idea Longbow. I know I have some of that around here somewhere, may just have to try it.

[hansol]

Longbow, I think out of everything that has been discussed here, that is probably one of the most brilliant ideas suggested. Wow.

So in order to pursue this, a guy would need to have data for a safe, yet comparably "hot" shotgun load. Any of these for sale in factory ammo, or does a guy have to reload one?

[turbo1889]

Well, very interesting discussion here about pressure measurement. Thought I might chime in with my thoughts:

------------------------------------------------------------------------------------------------------

Peak Pressure Set Gauge Idea:

Thought of doing that myself -- figured on using a heavy bull barreled single shot gun along the NEF-USH line. I was going to use a liquid filled hydraulic pressure gauge for measuring pressures up to 30-K with a built in isolation diaphragm. Bore straight through into the side of the chamber directly perpindicular to the barrel surface at about a 45-degree angle rotated to one side from straigh vertical (so I could still get a straight sight picture on top) about an inch forward of the breach and tap and thread the hole and screw the gauge in. Take the intended test hull and very carefully cut a hole in the side with a sharp razor knife to match the pressure gauge entry point and then carefully insert the shell aligned with the gauge. Measuring straight from the inside of the hull just forward of the brass head and through the plastic side wall with a full diameter hole not a pin-hole leading straight into the gauge should read full chamber pressure not no fraction. Never got around to doing it, but theoretically it should work with the exception of the fact that most likely the gauge couldn't react fast enough to measure the true pressure. The new fangled electronic not analog hydraulic gauges might be able to react fast enough to measure the peak pressure. Never actually put the thought into practice myself

Measuring case expansion:

Well this can work, main thing you need to realize is that different cases are stronger/weaker than others. So if your going to be loading with lets say Rem. gun club hulls you need to do your initial "factory pressure" test group with those same hulls. Secondly expansion measurements in a tightly enclosed chamber are slightly less reliable. If possible try to use a gun with a less than perfect chamber. For example I have a Braztec 410 shotgun that has a faulty extractor. The extractor is like an 1/16 of an inch off from matching the rest of the chamber cut. This leaves like a 3/16 wide lengthwise rib shaped bulge down the bottom of any case fired in it. Light loads leave only a slight bulge, full power 3" maximum loads leave a prominent bulge and overpressure, hot loads leave an ugly ironed-in, squared off bulge (don't ask how I know). Not only do the differences show up with a micro-meter or caliper but they are visible with the naked eye to anyone who isn't half-blind. This is a case of un-inhibited case head expansion, for that bottom part of the chamber on that gun only the strength of the hull itself is holding back the pressure and it isn't getting any help for the barrel steel -- obviously this results in an amplification of any pressure signs due to head expansion and thus it is very easy to read pressure on this gun. For initial load development you don't even need a measuring device, visual inspection is plenty. I've been looking over 12ga & 20ga guns ever since I picked up that little 410 Braztec hoping to find others with a similar flaw that is a lemon I can definitely make some good lemonade out of, haven’t picked up any more yet -- not quite to the point where I would want to deliberately create such a flaw, but push comes to shove it is an option.

My Own Commercial Idea:

What I would really like to see someday is "precision pressure check primers" these would be special primers available in various sizes and pressure ratings with a very dome like spherical shape to them. Load your cartridges with these primers and then fire them. If the half sphere shaped primer doesn't flatten out then your load is under the pressure listed on the primer box. If it does flatten out your load is over the pressure listed on the primer box. Each different level of these primers is made with a different thickness and strength metal cup. If the cup flattens -- pressure above rating, if it doesn't pressure -- below rating. Figure I could charge like $10.00 for little itty bitty boxes of 10 count of such primers and make myself lots of dough. I know I'd pay that much for them myself. Make some 209's that flatten at between 11&12-K and just work your load up until they flatten and drop back down a notch and you've got yourself a good safe home-cooked load. In addition some pistol primers that flatten out at about 30-K and some rifle primers that flatten out at about 55-K could definitely be put to good use as well.

[missionary5155]

Good morning
Turbo .. that has an interesting line there. I am gonna think on this as I head up the mountain today.
Mike in Peru

[blysmelter]

sorry to break your dreams, but you will not find a pressuregauge of such range and quality for 20$, not 200$, maybee at 2000$. Remember-the peak your are to measure is somwhere betwenne 750 and 1200bar and is present for a very short period of time. How much you will have to pay for a non-returnvalve at this rating I do not want to know.

[klcarroll]

Hmmmm........

I too have been considering building a pressure test setup.

.....But I was thinking of using "primer setback" against a "crusher" as a means of measuring pressure: .....An thereby eliminating the need for a drilled barrel and modified cartridge cases.

Kent

[hansol]

Hey guys,

I just wanted to take a moment to thank everyone who has participated in this thread so far, and have suggested such ingenius and clever ideas. I'm pretty sure it is only this forum where a guy can come up with a bit of an "irregular" idea, and rather than having everyone slander and bitch about how it isn't the norm, people instead are more than willing to discuss the merits and flaws of potential ideas in a regular, casual fashion. No name calling or dismissing things outright because they differ slightly from the status quo.

So just wanted to say thanks to all you guys who have chimed in, and didn't allow for this thread to degenerate into one of those "that's impossible/dangerous/stupid/crazy" threads.

[hansol]

Alright to take this thread in another direction, here are my current wonderings:

Regarding Round ball versus Bullet/slug penetration.

Through my reading of the old books on Africa and India, I've come across discussion of the standard round ball loads compared against conicals. And one of the interesting things that seems to be noted repeatedly is that the round balls tend to penetrate better, and in a straight line, when compared to conicals.

This too was noted by surgeons in the crimean war, where they noted how while the round ball wounds tended to be straight "in and out" affairs, with the balls destroying everything in their path, the conicals tended to impact something hard, and then be "turned" into the softer flesh, and proceeding to travel on a path of least resistance.

This too is seen in many wounds on the current battlefield, with small caliber bullets impacting bone and winding up in strange places perpendicular to the original direction of travel.

Has anyone else here noticed that their round ball loads tend to penetrate better than conicals?

[hansol]

Hey guys,

Thought I would post this up, so if anyone ever gets as desperate as me for a custom mold, they know how to make one. Granted, I will say right up front this mold doesn't throw perfectly round balls, but that is due to my lack of machining skills. So anyway, I'm poor at the moment, but wanted a way to fire some round balls in my slug gun project, so I made this thing up. It's pretty simple, all you need is a block of aluminum, some drill bits, and patience.

The process is simple: take your measurements, drill a pilot hole to the correct depth. Then use a bigger bit to take most of the "meat" out of the block. Lastly, finish with your "round" bit to make the final shape.

To make a "round" bit, all I did was take a spade bit, cut the nose off, and then file it to make it round. Unfortunately I didn't have any gauges to measure a perfect circle out, so I had to eyeball it. I was out by .005 on each side, so I think I did pretty good for a first effort.

Anyway, start with this:
http://i129.photobucket.com/albums/p204/hansol04/mold001.jpg

Then take your measurements, and bore out some holes:
http://i129.photobucket.com/albums/p204/hansol04/mold002.jpg

Use a c-clamp to hold everything together, and start pouring:
http://i129.photobucket.com/albums/p204/hansol04/mold003.jpg

End result:
http://i129.photobucket.com/albums/p204/hansol04/mold004.jpg

Here is the "round" bit, and a normal spade bit for comparison:
http://i129.photobucket.com/albums/p204/hansol04/mold005.jpg

Anyway, there it is. I know I was a bit brief this time, but I'm sure most everyone can figure this one out. Cheers.

[Red River Rick]

Hansol:

Did you find the 0.730" diameter R/B mould you were looking for?

RRR

[briang]

Nice work

[hansol]

RRR,

I did find a few makers of a .730 mold, but the prices are pretty high for me at the moment. I guess a .730 is a pretty oddball size, so the molds are expensive. There was one on ebay, but the guy won't ship to Canada...

So with all that going on, I just decided I would have a go at forming my own. And it worked out pretty good. The balls it throwns aren't quite perfectly round (really damn close though, I was out .005, and I don't have a lathe), they are more of a slight "pill" shape, but a little bit of teflon on the "flats" brings the width up to .728"- .729-ish. All that being said though, it turned out really well, and I won't hesitate to fire the balls this mold throws.

[turbo1889]

Hansol, if it turned out slightly undersize that is actually a very good thing -- this means you can lap it out using a ball cast from the mold which will allow you to hit 0.730" almost dead on if your patient and willing to lap, cast, check, repeat several times until you get the magic number. This procedure will also smooth out your mold to mike nice smooth casts.

I'm going to do exactly this procedure to one of my own round ball molds this afternoon -- it's suppose to be a 0.625" ball mold but it casts a little on the small side with my WW alloy and is also slightly rough on the inside. I will take pictures and post them to demonstrate the procedure. Expect posting early tomorrow morning.

In addition your mold doesn't seem to have any alignment pins so next time you have it clamped together and all lined up you might consider taking a long drill bit and boring through both halves on each side so you can put bolts through with wing nuts. If it were me I'd use an extra long 1/4" bit and then 1/4" long bolts and wing nuts -- but up there you guys use metric stuff so something similar would be in order. This would make the mold self center when you put it together and would also mean the bolts and wing nuts would hold the mold together and you wouldn't need the clamp at all.

And as far as the whole improvised pressure testing discussion goes, yes I agree the main problem with using a pressure gauge approach is that finding a gauge that would react fast enough to measure the peak pressure not just the average pressure for the test load would be the main problem -- I think that's the whole idea behind using electronic strain gauges to measure pressure in the commercially produced "for home user" units. Those electronic strain gauges are about the only thing capable of reacting fast enough to measure to peak of the pressure curve. Those little electrons move at like over half the speed of light you know. Such a pitty that they cost like $600-$700 plus $800-$900 for a decent lap-top to go with them to run the software. In addition someone mentioned placing thin disks or strips of either metal or plastic behind the case inside the breach and then checking with a micro-meter -- aluminum has very little spring back, aluminum pop/beer cans are made of very thin aluminum sheets; just a thought.

[turbo1889]

Okay, here is how you lap out a ball mold to both increase the diameter slightly and even and smooth every-thing up.


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What you will need to lap out a ball mold:

http://forums.handloads.com/uploads/turbo1889/2009-04-02_095310_Start_With_Small.JPG





Step-1, drill about half way through a ball cast from the mold:

http://forums.handloads.com/uploads/turbo1889/2009-04-02_095320_Drill_Ball_Small.JPG




Step-2, open the drill chuck all the way and put a long dry-wall screw down inside head first and then tighten down the drill chuck and screw the screw into the hole drilled in the ball, nice and tight:

http://forums.handloads.com/uploads/turbo1889/2009-04-02_095330_Attach_With_Screw_Small.JPG




Step-3, Apply lapping compound to ball:

http://forums.handloads.com/uploads/turbo1889/2009-04-02_095344_Apply_Lapping_Compound_Small.JPG




Step-4, lap out each half of the mold seperatly:

http://forums.handloads.com/uploads/turbo1889/2009-04-02_095355_Lap_Mold_Halves_Small.JPG




Step-5, put the mold back together and then lap the whole thing together through the pore hole:

http://forums.handloads.com/uploads/turbo1889/2009-04-02_095408_Lap_Closed_Mold_Small.JPG




My mold was an iron mold and it took three different lap/cast/check/repeat sessions to bring the mold out about 4-thousandths from casting at 0.622" to the 0.626" with WW alloy that I wanted. My 0.625" measured 20ga. rifled slug gun bore loads will be much more accurate with the ball just slightly tight rather than slightly loose. Your mold is aluminum and thus material will be removed at a much brisker pace about two to three times faster in my experience, you will have to check to be sure but each treatment session should bring the mold diameter out about 3 thou.

As long as you don't push down on the drill while your lapping and just let it float more material is removed out on the outer edges of the spinning ball then elsewhere and that's why I lap on two different axis (steps 4 & 5). You said your mold made pill shaped casts so you want most of your lapping to be done on an axis (direction the screw/drill is pointed) along the longer length of the pill so that the most material removal occurs at the outer "equator" (think of how the earth spins and where it's equator is) right where the mold is under diameter and it needs to be slightly increased. Lapping only removes a little at a time and as long as you cast and check in-between lapping sessions (use the balls cast to do the next lapping) you should be able to get your mold nice and round and right on diameter to within a couple thou. or so.

And oh yes, the lapping compound containes a light grease and any of it left behind will make your mold cast wrinkled balls. So inbetween lapping sessions where you cast balls to check how much the diameter has been increased by and to have the next size up balls for the next lapping. Before you try to cast wipe out the cavities with a shop rag or paper towel, spray a squirt of brake cleaner into them and then wipe them out with a paper towel (re-usable rag not option this second "clean wipe" time). This eliminates the anoyance of having to cast several times to burn out the grease and get good non wrinkled casts again.

[TooManyMisses]

FWIW , you should be able to find someone with an Oelher Chronograph and a strain gauge, all that is required as far as I know is to solder the lead on and you don't have to do any other changes to the firearm.

Has to be some one here in Canada with one of those rigs.

[Screwbolts]

many of you may find tis thread of interest, it is called, 12 Ga from HeXX: http://www.practicalmachinist.com/vb/showthread.php?t=126971

[Tokarev]

Has anybody tried to shoot jacketed round balls, where lead ball is cast into a copper hollow ball?

[missionary5155]

Good Morning Tokarev
It is an interesting idea.....
But make a copper ball filled with lead? Penetration maybe. No leading... But the WORK...
If penetration is what you want go to a Ball Bearing in a wad. For no leading just a dobber of regular boolit lube with do.
A WW RB will penetrate an Elepfhants head to the brain.
Mike in Peru

[Tokarev]

Some memories from the past tell me that there were round hollow spheres made of copper somewhere some time. I can't remember exactly where I saw them, perhaps on an old cupboard as knobs?.. Would be LONG time ago.

That's what I was thinking - taking a hollow sphere and filling with lead.

Ball bearings ricochet like crazy.

[blysmelter]

RRR,

I did find a few makers of a .730 mold, but the prices are pretty high for me at the moment. I guess a .730 is a pretty oddball size, so the molds are expensive. There was one on ebay, but the guy won't ship to Canada....

A bit late for you but anyway; Jeff Tanner will make you any roundballmould, a .730 costs 40US$, and he ships to anywhere.

http://www.jt-bullet-moulds.co.uk/moulds.htm

[hansol]

Range Report

Hey guys,

Made it out to the range today to do some more testing on the slugs. Shot a few paper targets, but also did some penetration testing on hard-pack consisting of old Outdoor Life and Field & Stream magazines.

For this test, I used 3 rifles: a 45-70, my 375 Taylor, and my SxS slug gun. Approximate velocities of each (as I still don't have a chronograph) are 1800fps, 2450fps, and 1400fps. Distance to target was about 10 yards, and test medium was dry magazines.

Results

Penetration:

.729 cal 580 grain slug @ 1400fps = 3 3/4"
.458 cal 350gr Hornady FN @ 1800fps = 4 3/16"
.375 cal 300gr Hornady RN @ 2450fps = 5 3/16"

Weight Retention

580gr Slug @ 1400fps = (shot #1) 492gr (shot #2) 564gr
.458 350gr @ 1800fps = (shot #1) 99gr (shot #2) 144gr
.375 300gr @ 2450fps = (shot #1) 81gr (shot #2) 231gr

So the above are the results. Interesting thing is that the slugs penetrated almost as deeply as the 45-70, yet retained weight much better, AND caused a "wound trail" that was the size of a small fist. The 375 penetrated the deepest, and also made a very large wound trail. The 45-70 shed its jacket both times, and caused a wound trail that looked like a mouse chewed its way through the hole. Lots of little bits of paper compared to the other two.

http://i129.photobucket.com/albums/p204/hansol04/Picture001.jpg
(Top left: slugs, middle: 375, right: 45-70. Bottom Left: Slug recovered at 50 yards in dirt backdrop (Weight Rentention = 568gr), Bottom right = .54cal Muzzleloader round ball)

http://i129.photobucket.com/albums/p204/hansol04/Picture002.jpg
Close-up of slugs

[Echo]

Don't know if anyone has mentioned it, but it seems to me that it would be a simple task to make a die to 'bump up' the tubing bullet from.702 to .729. Swaging down is a no-no, due to spring-back of the jacket, but you could bump the bullet up to whatever size worked best. As long as you used pure lead, should be able to be done on a regular (well, at least regular compound) press. wouldn't need the masking tape...

[Tokarev]

Swaging down is fine, just anneal the cup beforehand. There is no such thing with metals as an impossible shaping operation.