Originally Posted By: TwiceBarrel
Originally Posted By: JohnfromUK
Originally Posted By: damascus
SIMPLE DONT DO IT!!!!!!!!!! GUN SCRAP YOU HOSPITAL SOONER OR LATER.


Quite right. Speak to any reputable gunmaker who has made 2 1/2" guns, or either of the Proof Houses and they will say "don't do it".

You can't get better advice than the maker or the Proof Houses.

The fact that of course it doesn't always burst or cause obvious damage at the first shot doesn't make it either sensible or safe.


John our Colonial gun makers made guns which are considerably stouter than those made by the British trade and your CIP standards versus our Colonial SAAMI standard reflect that. Testing by two highly respected researchers, Sherman Bell and Tom Armbrust plus years of actual use have verified that firing 2 3/4 inch ammunition in a sound firearm with shorter chambers is quite safe. Bell/Armbrust tests show that firing standard 2 3/4 inch shells in shorter chambers increases the chamber pressure in the neighborhood of 400 psi or roughly 4%. I personally don't shoot 2 3/4 inch shells in my horribly outdated and unsafe guns with Damascus barrels but have no qualms about shooting them in my post 1920s steel barreled guns all of which are 16 gauge with 2 9/16th barrels.


My own (limited) knowledge is UK (gun and cartridge) based. I know personally where serious and expensive damage was caused to a fine gun by a few hundred 2 2/4" cartridges. It isn't necessarily a barrel issue, but simply the higher pressure/load/stresses the gun/action/woodwork are not suited to take. I do fully accept that many in cases all will be fine (and people who know what is involved will use suitably loaded cartridges), but as a rule its not wise to exceed the Proof House, or gunmakers design intentions.