Making a rifle barrel

[okawbow]

I've always been the type to make anything I think I can. Since I was a kid; I've made bows, arrows, muzzleloaders, violins, guitars, and just about everything else I could think of. As a young boy; I read a story about a gunsmith making a rifle, and using a handmade rifling machine. I've always wanted to try rifling a barrel.

I've had a piece of 1" seamless tubing, 44" long, with a ..495 hole, for 25 years, just laying on the steel rack. The other day, I took a long steel rod, and brazen it to a .500 reamer. I reamed the bore of the tube, and it came out smooth and shiny. I bored and tapped the breech end for a 5/8-18 plug. I used a steel bolt that was drilled and tapped for a nipple, to proof test the tube.

I loaded it up with 240 grains 3f, and a 370 grain maxi ball, pounded down. I suspended a hammer from a string, and used it to remotely fire the tube, that was clamped to a pallet. I fired it off several times, and as it was still in one piece; I measured the OD in several places. There was no swelling or distortion.

It seems that this tube is fit to spend more time on. I plan to make a rifling bench, and try to make a real barrel out of it. If it works out, I would eventually like to make a long, heavy chunk gun barrel, out of some 1 1/2"od x .500"id 1026 tube.

Anyone else every rifle seamless tube?

[JTR]

Type seamless tubing into the Search function above, and you'll get about 30 answers!
John

[jerrywh]

Everybody needs to make a rifled barrel at least once. then they will know what it's worth.

[okawbow]

I've read quite a lot about seamless tubing for thin smoothbore barrels. I think this a different animal. The barrel walls are .250 on this tube, and .500, if I use a 1 1/2". That's also why I did an overload test. I'm satisfied it's strong enough after testing, but I wouldn't use it unless I proofed it.

[Pennsylvania Dutchman]

The thick walled seamless tubing that you are talking about would be pierced and drawn from a larger piece of steel. It would not be welded and drawn like thinner walled tube. There would most likely be a lot of stress in the tube as is from the drawing process. You can send it to a heat treating shop to have it stress relieved to make it stable when you do the machine work on it. Stress relieved, it would probably be more stable in firing also. It wouldn't crawl and move as much with the heat from firing.
Mark

[JCKelly]

One may stress relieve that tube by heating to about 1100-`1200F for an hour, or couple of hours. Then just let it air cool.

You can guesstimate the temperature as this is about where steel just begins to glow in dim light

Do you have a big back yard where you can light fires? dig a long pit, build a wood fire, maybe add charcoal...when the flames have died down bury the tube horizontally in the hot coals, bank the fire & come back the next day to get the tube.

Not a-gonna look it up now, but betcha Dillin and/or Roberts have something to say about this. Maybe they call it anneal, maybe it was, but a stress-relief is something done at lower temperature. Either treatment would be a good idea for you cold drawn tube. Read the OLD books that describe what real rifle makers did, perhaps there is more to be learnt there than from . . . whoops! Gotta be polite.

Or, go to Harbor Freight and get a laser infrared temperature measuring device, good for about 1200F

Ideally the tube should be hung for this stress relief. Otherwise it will kinda bend of its own weight at temperature. Not possible in a back-yard pit, just try to lay it flat. 

[okawbow]

I'll probably take the 1" tube, and another 1 1/2" tube I'll buy, to someone with a large enough oven to do the job. I'm in no hurry, so can wait for them to hang it in there with someone's welding job to be stress relieved. I may also have it normalized, which would make the steel tougher and easier to work.