doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Damascus barrel wall thickness

I have run across a gun I am interested in with nice 12 gauge damascus barrels. The gun shows proof marks for 1 1/8 ounce nitro but the min BWT is .022. In a steel gun this would not really concern me shooting 2.5" lite shells but wondering what others think in a damascus gun? The barrels are at least 100 years old appear to be in original condition. I did not measure these myself and have not heard back on if this is a single low spot of a consistent measurement and to where exactly down the bore this occurs.

Side question, can a gun not be considered best quality if an under lug protrudes through the bottom of the frame?

Thanks for any input and I recognize this is a hotly debated topic... I am not looking to start an argument but just hear a few opinions (hopefully based on actual experience).

That measurement should around be 9" from the muzzle. If all other measurements show the gun is still in proof, there is no major pitting or bore problems, etc. I would personally not hesitate to use the gun. You need to have a qualified SxS smith give the barrels and action a good going over. If the smith in mention doesn't understand proof marks, doesn't use a bore mic, or doesn't have a wall thickness gauge, your in the wrong shop for this type of thing. Also don't expect him to grade it "safe" or "unsafe" to shoot. Most guys wouldn't tell you that about a modern gun, much less something one hundred years old, damascus or fluid steel for that matter. Expect more of a statement of the facts, the gun is still in proof, wall thickness is as stated, metal shows no dents or pitting, the action is in good working order. Things like that. .022" wall near the muzzle end of the gun doesn't worry me, as long as everything else is kosher. Ultimately, the decision will be yours. Just remember that the guns of that period were built to handle nitro loads with pressures of around 7,000 psi and shoot it with loads appropriate to that period.
You're probably right, this may start a small maelstrom of differing opinions, but most here are better educated on these matters than the average, so it shouldn't get too bad.
Luck,
Jim

Get a dial caliper and set it on .022...

Jim, you might want to edit this ( .0022" wall near-) It might give someone the wrong idea of safe.

If you don't have a dial caliper, put 7 sheets of copy paper together.

You better have some thin paper.

"IF" the gun blows up from being over pressured it'll blow at the chamber where the walls are thickest, not out where they're the thinnest. Walls of .022 out in the forward third of the bbls will not take as much of a bump without denting as thicker ones bt they aren't going to blow-up unless they have some other problem. In fact most smokeless loads will not stress them out there to quite the extent the original black powder loads did.

More information http://docs.google.com/Doc?id=dfg2hmx7_220dpc9nsck

Plenty of good guns available out there,if you need to ask the question you probably have the answer......I would just move on and find something else

CJ

I may be 'all wet', but I don't know if I agree with 2-piper's assessment of where the gun will blow up should that happen. With steel barrels (this may not be true of damascus???), barrels made of chopper lump construction will blow up at the area where barrel wall thickness is least (ie, just prior to choke). With monoblock, the weakest point is at the weld and therefore, they have a tendency to blow up there at the breech. Hence the added expense and safety of chopper lump over monoblock construction(however this may only be true with barrel obstruction??). Please correct me if I'm wrong, but it doesen't make sense to me that these damascus barrels would blow up at the breech or chamber of the gun if they were to blow up unless that area is where the weakest weld point is???

I've heard reports, from guys in and around the London trade, of guns passing proof at as little as .014". These would certainly be prone to denting easily, but would not be at risk of "blowing up". If they did, it would be do some sort of obstruction in the muzzle. With a muzzle obstruction, somethings going to give anyway. I'd rather that be as far from my face and hands as possible.
Jim