Crude comparison, small pistol primer hardness


Nov 24, 2010
Springfield, MO
I currently have 4 brands of small pistol primers on the shelf. I want to conserve my Federals and use the others for practice and play. So I compared the firing pin indentations on CCI, Winchester, and Servicios Aventuras primers using my S&W Model 60 J Frame snubby in double action. The photos show side by side comparisons. The Winchester and CCI primers are pretty close to the same, with the Winchester perhaps being a bit softer (bigger, deeper dent). The firing pin impression on the Servicios Aventuras primers are considerably smaller, indicating a harder primer. Although these three SA primers ignited on the first strike, my experience at the range has been that SA primers do not always ignite on the first strike in this revolver.

I am interested in hearing your experiences with these and any other primer brands you care to mention.


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I’ve always considered Fed 100 and GM, and WSP to be very soft. The Feds are my ‘cold dead hands’ primers.
WSPM are my favorite mag primers, soft, yet hot for good ignition on tough to light powders.
Historically Federal have been the softest for me. My lightest sprung revolvers only run 100% using their LPP. If I switch to SPP’s many brands will function 100% though, so they are easier to ignite than LPP, as a group.

Years ago, I had devised a sort of “primer dyno” just using falling (adjustable weight) on a linear guide but once I learned what I needed to know, I never got around to it.

CCI’s seem to be the last to show pressure signs, leads me to believe they are on the upper end of “tougher”. I use CCI SRP in my 9mm major loads.
In the NRA metallic reloading class I attended the instructor showed a chart indicating CCI as the hardest primers and Fed as the softest.

My tuned Kframe always ignites Federal, SA and DA. Winchester ignites 95% in single action, 60% in double action. Remington ignites maybe 80% in single action and rarely in double action. Never bothered to try CCI in my revolver, though in my 380 auto I have to restrike maybe 1 in 10 CCI (ignites Winchester 100%).

So I've come to prefer federal for revolvers and Winchester for autoloaders. Just yesterday I had an incomplete burn and squib in 45 with a CCI LPP, though first time I've seen that in thousands of them (WST powder).
Just yesterday I had an incomplete burn and squib in 45 with a CCI LPP, though first time I've seen that in thousands of them (WST powder).

I, by NO means, doubt what you say....
But a primer doesn't detonate just a little, either it goes POP, or it doesn't....
The incomplete burn and the squib weren't caused by the primer...........IMO.........
I would have to look harder at the powder......
Federal SPP are considered to have the thinnest cup. The competition revolver guys around here run them because they go bang when shooting DA with lighter springs.