SAAMI (voluntary) pressure standards are LESS than CIP "Superior Proof" standards, which carry the force of law, and we've had this conversation over and over ed.
But I'll play along in that someone may actually be interested in this.
Great Britain adopted the 1969 Commission Internationale Permanente pour l'Epreuve des Armes à Feu Portatives standards March 1, 1980 but continued using Lead Crushers to measure pressure until 1989.
BAR however was not introduced until 1989, and the imperial proof marks could be requested from 1984 to 1989 using the Tons SERVICE pressure while the metric version used the Kg PROOF pressure.
2006 British Rules of Proof added this:
Part IV, “The Proof Load”, Number 27, Part A
Calls for a load of 30% over mean service pressure at a point 17mm or 25mm (about 1”), and at a point 162mm (6.38”) from the breech face a load of 30% over mean service pressure (at that point as determined by the Proof House).
The powder used in proof loads is not specified.
I do not know if Black Powder proof only can be requested but there are not separate Black Powder standards in the CIP regulations.
12g 50mm, 65mm, and 70mm “Standard Proof” lead or steel (limited to no larger than 3.25 mm and max. fps 1,300).
Numbers are transducer BAR converted to PSI.
Maximum Average (SERVICE) Pressure 740 BAR = 10,733 psi;
Maximum Statistical Individual Pressure 850 BAR = 12,328 psi
Mean PROOF Pressure 930 BAR = 13,489 psi
12g 76 mm = 3” LEAD “High performance/Superior Proof”
Maximum Average (Service) Pressure 1050 BAR = 15,229 psi
Maximum statistical individual pressure 1200 BAR = 17,405 psi
Magnum proof 1320 BAR = 19,145 psi
SAAMI 12g standards
Load pressure
Maximum average pressure for 2 3/4" and 3” shotgun shells will be 11,500 PSI +/- 900 psi, with some maximum extreme variability not to exceed an uber-max of 12,500 psi +/-900 psi
Proof loads:
If a manufacturer uses a SAAMI proof loads, then the gun will be proofed by a lot of no less than 10 shots of ammo loaded to a maximum proof pressure of 20,500 psi +/- 900 – 4600 psi, or uber max of 25,100 PSI; and, will be similarly a MINIMUM average proof pressure of 19,000 PSI +/- 900 – 4600 psi for an absolute minimum proof of 14,400 PSI.
12g STEEL regulations: the barrels should carry the High Performance Steel Fleur
de Lys stamp and be marked “Steel Shot”
Both 65 and 70 mm 16g standard is SERVICE 780 BAR or 11,313 psi;
MSIP 900 BAR or 13,053 psi;
PROOF 980 BAR or 14,214 psi.
Both 65 and 70 mm 20g standard is SERVICE 830 BAR or 12,038 psi;
MSIP 950 BAR or 13,779 psi;
PROOF 1040 BAR or 15,084 psi.
Vic Venters, Shooting Sportsman, March-April 2012, “CIP Proof”
“Although the Maximum Mean Pressures for service loads for standard proof (850 BAR) guns are 740 BAR, CIP regulated cartridge manufacturers typically work to lower pressures...between 450 (6,527 psi) and 650 bars (9,427 psi) as measured by CIP piezo transducers.”
