454PB
11-30-2020, 11:46 PM
Seems everyone is struggling to find primers lately, and I've seen many forum posts concerning the use of the "wrong" primer in rifles and handguns. I decided to do some comparisons via weighing some SP, SR, SPM, and SRM primers. It's known that all small size primers have the same external dimensions, large size primers do not, rifle primers being slightly taller than pistol primers. Many of the newer reloaders want to know if small rifle primers can be used in pistols and revolvers, since SP primers are hard to find now.
I've done some experimenting with the use of SR primers in handgun rounds, and so far have been successful using hammer fired guns, but I need to do more testing in striker fired guns.
I did some crude comparison by weighing CCI 500, CCI 550, CCI 400, and CCI 450 primers. I weighed 10 of each and found them all the same weight (3.3 grains) except for the CCI 450, which weigh 3.5 grains. I also weighed 10 fired CCI 550 primers thinking the difference in weight can tell me how much priming mixture is used. The result was .3 grains. reduction in weight after firing.
I've seen reports that SR primers have thicker cups, so I removed the anvils in several and measured the side wall thickness as carefully as is possible using a dial caliper. All 4 types measured .020" thick.
So the only real difference I could measure was that the CCI 450 primers are .2 grains heavier than the others. No real surprise, I expected more priming mixture in a magnum primer.
I've done some experimenting with the use of SR primers in handgun rounds, and so far have been successful using hammer fired guns, but I need to do more testing in striker fired guns.
I did some crude comparison by weighing CCI 500, CCI 550, CCI 400, and CCI 450 primers. I weighed 10 of each and found them all the same weight (3.3 grains) except for the CCI 450, which weigh 3.5 grains. I also weighed 10 fired CCI 550 primers thinking the difference in weight can tell me how much priming mixture is used. The result was .3 grains. reduction in weight after firing.
I've seen reports that SR primers have thicker cups, so I removed the anvils in several and measured the side wall thickness as carefully as is possible using a dial caliper. All 4 types measured .020" thick.
So the only real difference I could measure was that the CCI 450 primers are .2 grains heavier than the others. No real surprise, I expected more priming mixture in a magnum primer.