Rocketman, the "magnum" thing is irrelevant as far as SAAMI is concerned. Only relevant as far as CIP is concerned, with a different standard for "magnum" proof. SAAMI standard for 2 3/4" and 3" is the same: 11,500 psi max avg pressure in the 12ga, 12,000 psi in the 20. As far as CIP is concerned, ALL American ammo is loaded to what they call "magnum". And all those French heavy proofs, as I understand it, are no longer current. CIP standard proof for 12ga is 850 bars; magnum is 1200 bars. Another of those cases of two peoples divided by a common language.
As far as CIP proof testing goes, certainly all guns are submitted to govt proofhouses. However, obviously all ammunition is not--only occasional lots. So it's certainly possible for CIP ammo to exceed CIP standards, just as it's possible for American ammo to exceed SAAMI standards. The former would be a violation of the law; the latter--if an accident resulted and if the victim could demonstrate that the ammunition in question exceeded SAAMI standards--would likely result in a serious lawsuit against the ammo maker.
