European cartridges have to be proof tested also (random samples from a batch) to see that they fall within safe limits compatable with the pressures for which the gun was proofed. Such ammo boxes will be marked with the CIP logo. Certainly the older American made Winchester AA cartridges imported to Britain and the Remington RXP's in the 1970's were found to be well over the safe limits for 2 3/4" chambered English guns. American ammo is quite punchy; or at least was then. Even if you have an English 2 3/4" chambered gun I would be cautious about using non-CIP ammunition. Lagopus.....
Lagopus, American cartridges are also proof-tested. The problem is that major American ammo makers don't worry about pressure as long as it does not exceed the 11,500 psi SAAMI standard. Nor do they indicate pressure on the cartridge boxes. That's why both Burrard and Thomas explained that the real issue was not the length of the fired hull, but rather the load in question. Burrard wrote: "It is true that all American fully crimped cartridges loaded with but 1 1/8 ounce of shot develop pressures which are considerably higher than those given by the corresponding British cartridges, but this is due to the relatively higher powder charge adopted by the Americans rather than to their use of a 2 3/4" case." That statement is no longer true if you include companies such as RST and Polywad, that specialize in light, low pressure loads. However, it is true enough reference the offerings from our major ammo makers that it would not be wise, IMO, to shoot most American factory loads in British standard proof guns, even if they have 70mm chambers--unless you know for sure that the pressure for the shells in question falls within the lower CIP standards.
Last edited by L. Brown; 08/04/13 05:47 PM.
