Craig, wood isn't proofed. Anywhere that I know of. But then wood failure isn't a safety issue for the shooter (except maybe getting a splinter or something, if it's really a catastrophic wood failure!) Metal failure definitely is . . . as we've seen from some posts on this very BB.
Buzz, it used to be that arms manufacturers had different proof standards. But, as can be seen from the proofmarks on old Parkers, Elsies, and Winchester 21's, they did indeed proof their guns. I cannot state with a certainty that each and every gun being produced in this country undergoes proof. However, SAAMI establishes the proof limits which all manufacturers follow (voluntarily), just as all ammunition manufacturers test their loads for pressure and velocity. (Obviously, of course, you don't get to shoot the shells they've tested!) But here's what SAAMI says on the subject, which leads me to believe that all currently manufactured guns undergo proof testing: "In spite of many years of research, no economical or simple substitute has yet been found for the complicated and expensive methods and equipment USED BY FIREARMS AND AMMUNITION MANUFACTURERS for pressure determinations." (Emphasis mine.) Even without a national proofhouse, given our litigious society, I'm pretty sure a lawyer could have a field day with a gun manufacturer that didn't proof their guns, in the event of serious injury to a shooter.
Miller, why do you insist on moving the discussion to what is or isn't loaded in 12ga guns, when we're talking about 20ga guns? The point is that 3" 20ga loads are both heavier and faster than they were back when those 3" Parkers were made--which both of us should know, since all we have to do is look at what was available then vs what is available now. Even if those guns would pass proof, does that mean they're good to go with a steady diet of those heavy loads? Of course not, particularly not century-old wood, even if the metal is OK. But then if I pick up an English gun proofed for 2 3/4" chambers and 1 1/8 oz loads, does that mean it's OK with any of today's 1 1/8 oz loads--including steel shot? Proof is not a 100% guarantee against either ignorance or flat-out stupidity, but it's better than not having proof. Were that not the case, why do we even have SAAMI's voluntary standards in this country? But if someone is going to volunteer to materially alter a gun, then he should be willing to volunteer to submit it for proof as altered, before that gun leaves his hands. Pretty much like--once again--selling a used car with the odometer rolled back. Not being able to do that is, IMO, a good law.
