doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Thoughts on TIG welding on a barrel

yah shooting with progressive light charge loads might work but what happens when owner passes and next owner stuffs it with hot factory loads? duh that sounds like setting a trap for the next guy. just take your lumps and scrap the barrel as several responsible people wrote here.

Nitro, it is not mine to scrap. I am just trying to possibly help someone that has this gun.

Brophy's "Plans and Specifications" book on p.21, on a drawing titled Straddle Mill Lug. gives the barrel material as approximately .40 carbon, and on page 204 in a table of materials for the various parts, lists the barrel as being made of SAE 1020 steel. In either case it is a low carbon steel and shouldn't be subject to hardening from heating and cooling. This is also verified by the fact that the lug and the rib extension are brazed to the barrels with no ill results. I believe that a skilled welder could make this repair by TIG welding and that it would be as strong as the original barrel.

Tom, as always thanks. I should have looked in my book also.

jdw; be sure to pass on full range of comments including those taking prudent approach to scrap out barrel. On second thought why isnt owner posting here to get information first hand? its easy to set up account and sign on. first questions he should ask welder is if man will guarantee barrel wont blow, burst or split with normal factory loads not cream puffs? and if the guy has liability insurance for gun barrels? if the answer to any of these is NO then owner knows what to do with the barrel.

Oscar had a welder that did a number of welds on damascus barrels for him.

I wonder if anyone here could help you find that welder?

I'll say again, it does have enough carbon in the barrels to harden and it does indeed harden from TIG welding and the self quenching caused by room temp barrels. No reading between the lines or specs. BTW, .40% is plenty of carbon to facilitate hardening. 4140 can achieve 500 Bhn or 50 ish RC. That's pretty dang hard. Weld puddle borders can have concentrations of alloying agents, especially carbon, that facilitate even higher hardnesses. I have the dull files to prove it.

I don't believe 20th century LC Smith barrels were 1020 for a minute. 1020 is stuff you use for making muffler tubing not gun barrels. If you've ever machined 1020 you'd understand that it isn't suitable for machining a gun barrel either. It is so long grained and leaves such a poor finish that you would have to invest in additional finishing processes that cost a lot of time and money.

Mike, I'm sure there are a lot of excellent welders out there, thanks for replying.
The really good ones are the ones that will tell you whether they would do the job and what the preperation would be to do it.
Plus they would finish the outside and either magna flux it, x-ray it or the least would be to use the dye.

The thing I want to know from the skeptics, what makes you think this would "blow out" or be a weak spot, steel is going back into a cut. If the metal used is compatable to the barrels steel, what would cause anything to happen. It is not like it was a bulge that blew out and someone was adding a patch to it.

The pressure at 13" I would think is way down by now.
This is just my opnion and unles a metalugist can give a reason, I would, and a few others would like to hear it.

I will email the gentleman and direct him to this site, it is up to his friend on what he wants to do.

http://www.doublegunshop.com/forums/ubbthreads.php?ubb=showflat&Number=256810&page=2

This thread above has some pressure data and some wall thickness information posted. It looks like 2500-3000 psi is about where this cut is, of course, a lot depends on the max pressure of the cartridge.

"I don't believe 20th century LC Smith barrels were 1020 for a minute. 1020 is stuff you use for making muffler tubing not gun barrels. If you've ever machined 1020 you'd understand that it isn't suitable for machining a gun barrel either. It is so long grained and leaves such a poor finish that you would have to invest in additional finishing processes that cost a lot of time and money."

Chuck, Tom Martin was correct, the steel used for most L.C. Smith parts including the barrels and receiver was 1020 steel.

This cannot be for all, because most had different types of barrel on them and so I would imagine, other steels. The highest was Sir Josheph Whitworth, down to the lowest Royal Steel on the lowest grade hammer gun. I don't know what the barrels on this page are for, but it clealy shows 1020.

At the top right hand side, you can see the word Featherweight, so this has to be after 1907.

An interesting site on the properties of 1020
http://www.suppliersonline.com/Research/Property/metals/819.asp