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Heat treating
I figured I post this here. I know there is a lot of knowledge here about steel and heat treating.
I'm in the process of building a barrel for a custom Remington 700 in 223. The guy that is helping me build the barrel has told me to order a 416R heat treated and resulfurized length of stainless steel 1 1/4 inches in diameter by 30 inches long.
Heres the problem. The only place I know to get the steel from only get the steel that hasn't been heat treated. They want 160$ delivered. Is this a good deal? Also, where do I send the steel to get it heat treated?
I have no clue about the different steels out there or what resulfurized means. Any help would be appreciated. If you guys know of a place to order the stock from, that would be a huge help as well.
Thanks!!!
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i'm just throwin this out there.
but you could most likely get a top of the line, cut,contoured,rifled,threaded,installed,and finish chambered bbl for about $300.
if you are gonna do it yourself you have a ton of work and a lot of reading about how contouring a rifled bbl affects the internal diameter.
squaring faces to mate the bbl/action.
cutting threads.
and chamber reaming.
and buying/renting a reamer.
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I realize it would be easier but the process of making the barrel is going to be half the fun. The lathes we will be working on we're made during WW2. These lathes are nearly 30 feet long and there are only 8 of them left in the country. I will be doing a 6 1/2 gain twist, start to finish.
This will take us at least 8 to ten hours to drill and cut. Barrels made today are made in about ten seconds and are mass produced. No love.
The cost of the barrel is just a small portion.
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You know barrels are gun drilled, not with a lathe, but with a gun drill.
What is your setup for rifling? the Bill Webb Rifling Machine? Why 6.5 gain twist? you trying to shoot 90gr serrias? Those have been put to the side for 223 by all the shooters who's opinion I respect. (90's need more powder than the 223 can handle to be effective at long range, the only person I know who shoots them worth a damn does it with a 22-250)
And you can still buy cut rifled barrels from Kreiger, Obermeyer, and other top level manufacturers. Go to Kreigers website, there is a very good treatise on why they have such a hard time finding steel to make barrels that meet their standards. Something tells me that if you do find steel that meets that criterea, it is expensive as you have found out.
If your just hell bent and determined to cut your own barrel, Might I suggest that you find an old pulled barrel in a caliber that has a groove diameter smaller than the bore diameter of the caliber you wish to create? That way all you have do do is bore and ream out the old lands, then re cut the new lands, all with proper barrel steel. Competition shooters such as myself cull barrels when they start shooting off call and often sell them for $50 or so or sometimes even free. I have purchased many kreigers that were shot out to teach myself chambering. You should be able to find a shot out stainless .204 ruger barrel from some varmint hunter somewhere. How about a green mountian barrel blank in .204?
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or call some of the makers and just buy a blank from them.
no hole no nothing just the blank.
you'll at least know the steel is good and is from a certified batch of steel.
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Cool, is that lathe a LeBlonde? We have a few big 'uns at the shop I work in but they use em to turn 18k lb titanium ingots. I'd almost give money to see a little gun barrel in one! I'm not gonna try and talk you out of the project but I will say to start in on arm exercises now as nothing on those great beasts moves easily.
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There are lots of heat treatment companies. Find one and send it out. Being a machinist and tool n die maker I too am curious how you plan to rifle the barrel. Drilling it will be a real bear but rifling will be interesting on a lathe. Good luck.
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These guys are very good:
http://www.gmriflebarrel.com
These guys are also excellant:
http://www.kriegerbarrels.com/
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$160.00 delivered. A good price. No.
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Resulfurized steel is a type of steel (stainless or otherwise) that has a small amount of sulfur added to it to make it free-machining. Most stainless steel is a pig to machine.
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Agree with the perfesser's comment, it is accurate, as usual.
IMO, no heat treat is required for this application. Just normalized 416 is hard as the
hubs of hell, you will have a *itch of a time drilling and cutting it if you heat treat it harder
than "normalized" condition. Mechanical engineer with 38 yrs in industry and longer
as a shooter and home gunsmith. IMO, unless you will have carbide cutting tools, you
will be MUCH better served with 4140, again, in the "normalized" condition.
Bill
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Bill is right. The problem with most stainless steel is that the surface work hardens under pressure. Dull tools cause more pressure. Any machinist will tell you that when you cut stainless you have to cut it or get off of it. Letting a tool rub while the part spins is a sure way to make a surface that you can't cut through. Feed rates are set to be high enough that the tool cuts past the hardened layer .
Now in traditional barrel rifling you're using a scraper blade to cut a very tiny amount of material away under pressure. It works great with traditional barrel materials, but I have no idea if it will work on stainless. There is a reason that newer methods of barrel rifling have been invented.
That said, there is nothing wrong with giving it a try. Love to read about the outcome, you might just come up with a real winner. Carbide tooling and free machining steel gives you a fighting chance. Good luck!
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Having machined litterally lbs of 416 it is among the easiest SS to machine. As far as heat treating, there is not enough carbon in the material to get it much harder. It will work harden slightly but believe me this will be the least of your problems.
Barrels are drilled on a gun drill not a lathe, there are two types, one turns the stock, the other turns the drill.
Anytime the hole is deeper than 10 times the diameter, then gundrilling is the preferred method. Trying to drill the hole that deep on a lathe would result in a hole is about as strait as something that is not very strait.
Gundrilling is usually charged by the inch. The hole needs to be reamed to size after gun drilling, this costs more. The gundrill is a specialized design that makes it's own lead. The point is offcenter and the drill literally trepanns the hole. There is also an oil pump with many PSI output that pumps oil down the holes in the drill shank to push the chips out the hole. Without this the chips just plug the hole and you're done.
http://www.thompsongundrilling.com/ This guy is good and I have been using him for 25+ years
It is really not economical to do a one off barrel. It might be considered fun but it will be expensive and frustrating fun. I have 35 years in a shop, I farm stuff like this out because it is a complete nother lifetime of techinical expertise to learn how to do it, and also I need it done right.
Lots more to it than is readily evident. Lots more to it! Lots more to it! Lots more to it! before you jump off this cliff I advise that you actually go to a gundrilling shop and see what it is that they do. It is not a conventional machine shop by any means.
Maybe ought to buy a whole 12' stick of the 416 SS. The wasted parts will make good tent stakes. :kidding:
Randy
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HUGE +1 on what W.R. Buchanan said!!!!!!!!!!!!!!!!
You are making it even harder on yourself by trying to make a small caliber.
Are there any barrel makers in your neck of the woods? If so see if they will let you tour their shop. It may help you to better grasp what we are trying to do.
For your first try at rifling I would not use stainless as you are making things even more difficult for yourself yet and you can make cheaper tomato stakes.
W.R. is right this isn't going to be a walk in the park!
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I'll have to ask some questions when I get to his shop. I know that oil is pumped through the bit as the barrel turns around the cutter. I guess "lathe" was the wrong terminology. The guy that I will be working with normally makes barrels 50 cal and up including military barrels 20mm and up and six feet long. These tools are all a dull light green. I will get some pics and names of the tool.
I know this isn't going to be easy, just a kick butt introduction into machining my own barrel.
I am seriously considering clambering this barrel for the 22-250, as you are right about the 223 not being the best round for 90+ grain projectiles.
I plan on swaging my own bullets, so I won't be limited to stock bullets and so so consistency.
Does anyone have a location that I could order the blank from? Someone they trust? I've never used the weld shop in my area, so I don't know about the quality I'm going to be getting.
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Gun drills can turn as much as 6000 rpm (some of them). A 3000 rpm chuck spinning one direction and the drill spinning 3000 rpm the opposite direction. Gun drills don't cut big chips, more like little scrapings. You can see that stainless could work harden in no time in this situation. Takes about 1/4 inch of too fast feed in a bandsaw to harden 1/4 inch stainless and ruin a blade. (example) It has to be cutting or it hardens. Cut needs to get below previous cut's hardening or it's all over.
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There are a number of people who make quality blanks Here in WI.
A Bing search will show them.
If you want to use 90+g projectiles use this to determine your minimal twist rate.
http://kwk.us/twist.html
I would try to make a barrel if you can there is much to learn. I am just saying there is better material to start with and better(larger) calibers to get your feet wet with too.
It may be a VERY personally rewarding learning experience at the least.
There is a ton of stuff you will experience and hopefully understand, metallurgy, tooling, machining etc. .
If you are successful you may use the experience to promote yourself in other ways/expand your skill-set.
All we are saying is this is far more challenging than most folks realize.
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If you were using EDM to cut the rifling it would not really matter how hard the steel might be. I assumed from the OP's description of the age, etc. of the machines to be used that they are broach type or scrape type rifling machines, but you know what they say about assumptions!
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Despite all the nay-sayers, it must be possible to gun-drill stainless, since there's bazillions of stainless barrels in use already.
Looking forward to pics of the machine tool !
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It's not the drilling I would be concerned with its the rifling.
With EDM or hammer forging it shouldn't matter. With other methods it might.