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Veeb
April 22, 2012, 09:41 AM
I'm unclear about the real meaning of some of the proof marks found on, especially, old Webley military revolvers. For example, the nitro powder proof marks. What did such a mark really denote? What did the proof testing entail? I mean, did they fire six nitro powder rounds and give it the stamp if the gun didn't blow up? Did they fire a hundred? I'd be interested in any history or other info on this.

SDC
April 22, 2012, 02:33 PM
The history of proof marks is a study unto themselves, and there are a number of books on them; part of the problem is that each country (and sometimes proof-houses WITHIN a country) instituted their own system, each with their own accepted level of overcharge, type of powder used, weight of projectile(s), and so on. The "Nitro" proof dates from the realization that nitro powders placed a much more sudden and sustained load on a gun when it was fired, so they had to be proofed additionally specifically for those powders; the usual standard was at least a 30% overcharge, and if the firearm took that and didn't show any ill effects (no warping or measurable changes of the chambers, barrel, or frame), then it was assumed to be good for any standard load of that calibre/gauge. In the case of a revolver, they'd fire one proof load from each chamber, inspect the revolver from top to bottom, and then stamp it as having passed.

James K
April 22, 2012, 03:28 PM
Proof laws originated in England in the early 1600's when the gun maker's guild began to "prove" barrels in an organized way. They then used an old fashioned method known as bribery to get a Royal Charter that banned sales of guns not having the proper proof mark. The main problem was that the English gun makers were facing competition from Belgian makers, and the main idea was to keep out inferior foreign competition (of course to the English, any foreign product was, ipso facto inferior).

The idea was later adopted by other European countries, but the U.S. has never had a proof law or any legal standards for barrel proof. Most U.S. makers do prove their guns and mark them; but there is no law compelling them to do so. Winchester's WP; Colt's VP, and Remington's REP, as well as the military P are examples of private proof marks.

For the arms collector, proof marks can be used not only to show the country of origin of a gun, but sometimes where and when it was made or whether it might have been in another country. An example would be a Winchester rifle with British proof marks; it was certainly made in the U.S. but at some time it had been imported into the UK.

Jim

mapsjanhere
April 22, 2012, 03:48 PM
If you're really going to get into proof mark research, Wirnsberger's booklet (http://www.amazon.com/Standard-Directory-Proof-Marks-Wirnsberger/dp/089149006X/ref=sr_1_1?ie=UTF8&qid=1335127564&sr=8-1) is a good start. Not undisputed, not comprehensive, but a good start for a lot of countries for $10.