roll crimp

[Ed Blake]

Destry's right. A roll crimp will reduce pressure and velocity, but by how much and how you would offset any velocity loss, I don't know. The only thing I use a roll crimp for is blackpowder.

[George Blair]

From Bell's article The Forgotten Tens,in the DGJ 12-1. "To see what would happen, I tried a couple variations of this load. Having the test equipment allowed me to get answers to my most frivolous of questions. By leaving out one of the 1/4 inch filler wads, I had room for a six point star crimp on the smooth brass Winchester hull. With the same 38- grain charge of SR4756 powder, the velocity increased from 1202 to1288 ft/sec. The pressure jumped from 8100 to 11,000 psi! This tell me to stick with the roll crimp in my heavy loads for the 2 7/8inch ten-guage shell"