CIP shotgun PROOF specs.

[Guest cookoff013]

http://www.tiropratico.com/CIP/Tabelle%20CIP/caccia_tiro_press.pdf

[Wharf Rat]

[Guest cookoff013]

i asked for this to be a sticky, but no reply.

 

there is a few things that surprised me. as i mainly work to saami standards, but under 10500psi. (740 bar is 10,770psi).

 

even i was confused at one issue

"The pressure values of high performance cartridges and of the superior proof are valid for all calibres "

 

so you can have a 2,3/4" shell proofed to 1050bar, as long as the gun can take it its fine !

 

just write HP on it !

[clayman]

The whole aspect of chamber length being relative to pressure is a historic convention.

 

For bulky black powder loads, to push more weight of lead out at a reasonable velocity, you needed more powder in the case, and therefore a longer case and a longer chamber.

Modern cellulose powders take up little room in a shell case, and you can load a 2" case with enough modern powder to give what we would describe as magnum pressures.

 

Proof and loading convention still runs with the theoretical lengths needed for black powder loads - so a 1200kg pressure proof is applied to a 3" (76mm) chamber, a 900kg to a 70mm chamber etc.

 

While its uncommon, cartridges are sometimes manufactured to a 3" / 1200 proof in a shorter case - but despite the case opened being shorter than the chamber length they are still marked on the box as 3" magnum.

 

Even a 2" cased Magnum has been made, and despite the physical cartridge being only 2", the case length on the box is marked as 3" as they need a 3" proof to be safely fired.

 

The declared proof length of a cartridge can be different from the actual length in the box. Its always the proof length that is declared so that users choose appropriate cartridges for their chamber proof.