Proof & View Mark Question

[James Rogers]

This may be of interest to those who are trying to figure out the manner in which the original barrels received their proof marks. In London, the Gunmaker's Company proofed fired barrels in rough form AND in finished state. They used a double charge of powder and ball. Rows of barrels were tested at a time. The view stamp was applied after the rough form testing and the proof mark after the test in finished form. (Paraphrased from George)

[Acer Saccharum]

James, in your experience, are there any instances of barrels being stamped while hot, then finish bored afterwards?

[Pukka Bundook]

Acer,

Not with proofs and not with a gunmaker's mark.   
Most gunmakers bought in their barrels in the white, so their mark had to be added as the barrel was fitted and finished, and of course proofs were stamped when the gun barrel was to it's finished dimensions.
(plenty of makers fell foul of the Gunmaker's company, for filing barrels after proof.)

A blacksmith/barrel maker in the lands of no proofs could add His mark hot if he chose.

ATB,

Pukka.

[davec2]

A friend of mine just sent me this link a few days ago and I thought others might be interested in British barrel proofing circa 1951.  I had never seen the train of powder / sand trap set up for proofing barrels with temporary breech plugs......still not clear how the 18th century 3D stamps were made on barrels without severe damage to the barrel ID.  I know Mike said some of the original barrels he used were dented in the powder chamber, but knowing how hard you would have to hit the stamp to make nice, clean, 3D impressions (like those I have seen in photos), I would think the barrels would be more than dented.   



James Wilson Everett !!!  Where are you ?  Any ideas on this topic

[jerrywh]

Mike,

OK....so you smack the bejeeses out of it 6 times with a 4 pound hammer.....so how do you keep from distorting the bore ?

Dave . This is just my opinion but they had to put a mandrel in the bore. I don't think they cared if it deformed the bore a little. That would not effect the accuracy any.

[G_T]

Goo,

For hallmarking and maker's mark in precious metals, I went the opposite direction. I now use a rather heavy hammer and strike relatively slowly with it. I do not get rebound that way. The item being stamped needs to be well supported. YMMV of course!

Folks, please don't consider this advice for stamping steel or iron barrels. I've never done it. I'd likely engrave instead, though my engraving isn't good by any modern standards.

I do know that some stamps are designed to reduce metal distortion around the pattern, whereas others might be designed to make a very sharp impression. I'm thinking the former would make more sense for stamping a barrel.

Gerald

[davec2]

Jerry,

I think you are correct.  Just like the two immutable laws of physics (don't pull on a brick, don't push on a rope), there is no getting around the amount of force you need to apply to move metal like that.  A mandrel would be the only way to keep the bore even sort of round.

[Flint62Smoothie]

Consider that the iron used was soft.  Even the famous stub twist barrels were just made of iron of different density.  The steel barrels of today probably make that job much harder.

Yes, I too believe the difference we experience today is in the form of the ‘metals’ used.