Pressures, chamber lengths, cartridge lengths, once more. Please bear with me.
I have a number of Winchester Super-X 20 gauge 2 3/4 (70mm) cartridges. All the fired ones measure a tad over 67mm. Since my Rottweil Tiger cartridges are 67 mm on being fired and this is the allowed length for 2 1/2 the Winchester’s and Rottweils are comparable.
The CIP maximum service pressure for 20 gauges from 65 mm to 70mm chamber lengths is 830 Bar which is 12038 PSI.
The SAAMI pressure is 11500 PSI for 23/4 inch (70mm) cartridges.
Given the length of the fired cartridges not being long enough to enter the forcing cones and causing a spike in pressure there and given that max SAAMI pressures are below CIP max service pressures, would Winchester cartridges be usable in a 2 1/2 inch chambered, in proof, in excellent condition, British side by side 20 gauge?
