doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Who can make me a set of barrels?

OK, my recipe from a reloading publication:
Federal Gold Medal Paper hull (full length 2 3/4")
Federal 12S3 wad (or 12S4 if crimp is incorrect)
Federal 209A primer
1 oz shot
17.8 gr Hodgden Clays powder
star crimp (factory style)
1150 fps
approx 6500 psi (tested in short chamber)

This is probably not a bad thing when compared to losing eyes or fingers from a burst barrel.

Still, I have imagined sending a nice gun to a proof house and not only getting back a blown-up gun, but having paid for it. Kind of like paying the surgeon even if Grandpa doesn't survive the operation... which is exactly what happens.

I think it would make for very interesting reading if someone were to do an article based upon interviews with long-time employees of proof houses. I wonder if they get a feel for which ones are going to let loose based upon make, barrel type, damage (i.e., pitting; external or internal, dents, wall thickness), or any other factors.

I think by the time they put a shell in a gun at the proof houses, they are pretty sure the gun is going to be fine. Someone posted the process here long ago. It involved detailed inspection for defects and dimensional inspections.

The proof house will reject any gun during initial viewing if they have any reason to believe it will not pass proof firing.

yes that is true, but some still fail.

That's what I thought Chuck, but it seems every time there is a discussion here about minimum safe barrel wall thickness, one or two guys chime in about a gun that has passed Nitro re-proof with very thin barrels. It kind of makes me wonder if the proof houses don't have at least one employee whose attitude is, "If you're stupid enough to send this POS in, I'm crazy enough to blow it up." I don't recall exact dimensions, but I do recall remarking on one that was out past the forearm that was only a few thou thicker than a matchbook cover, which is about .016".

Of course, I have also often wondered how how anyone knows if the obvious honing on a given barrel was done before or after the proof marks were put on.

That some fail is also true. This is why the proof process has three steps: pre-firing viewing, firing, and post firing viewing. Pre-firing viewing weeds out anything that can be seen/measured as not acceptable. Firing finds anything that inspection did not reveal. Post-firing viewing finds dimensional change failures (not all firing failures are dramatic and/or obvious).

I'm an American redneck and I don't believe anything I see in a proof mark. Yup, as Keith says, how do you know whether the gun was messed with after the marks go on. Use a wall thickness gauge and ignore all proof marks. I've never seen a proof mark that said "Look out for this one."

What would be interesting to know is, how many rounds do they use to proof it with?
Over here in the early days, most gun makers proofed guns their own way. L.C. Smith used twice the powder to proof theirs, and in the mid 20's I believe started to put the proof marks on the barrels. I'm sure most other American gun manufacturers did the same. But again, how many rounds did they use to proof?
I agree to what Bill said, who knows what was done to the gun since it left England, how many times was it re-blued/browned and how much was removed from in/out of barrels.
Like stated a wall thickness gage would make me feel better.

JWD: Recently it was rumoured that the London Proof House was double proof testing all guns but I never heard this as definitive and I believe that this has passed into history.
As regards lapping done after proof testing, this is why there is a 0.008-0.011" maximum proof range. However, if a barrel was proofed exactly on 0.728" it could be lapped out to 0.739 before being out of proof. Obviously in a barrel with MWT of perhaps 0.020" at 0.728" this would be a very thin wall at 0.739", 0.015"!
As regards pitting, the Proof House likes to see clean tubes but will Proof test a pitted barrel providing there are no substantial pits in the area between the ribs. Equally likely to cause a refusal at the initial view are rivelling, dents and bulges and these can be almost invisible. Rivelling and bulging caused by the proof test invariably cause the gun to be failed and a subsequent retest required after the barrel has been repaired.
On the matter of wall thickness, as we are specifically banned by law from exporting guns for any purpose (including wall hangers) that are out of proof, on the request of the owners I have successfully proofed guns down to the low teens. For obvious reasons, these barrels were not worked on after proof, all the lapping etc was done before.