Home Forums Hunting & Shooting AR and Tactical Rifles Light Primer Strikes

I’m going through a can of ammo that I put together out of odds and ends powders, and some bulk 75 grain BTHP bullets, and odds and ends primers. They all go bang in the gun, with the exception of the ones loaded with the Winchester primers. Those ones just get the tiniest little dimple on the primer. I assume it has to do with the hardness, or softness of the cup on those. Is that the correct way of thinking? Or could
It be something else?

most likely a headspace issue.

I'd check the case length (base to shoulder). Winchester primers seem to have softer cups than say, CCI. If the unfired rounds with Winchester primers are shorter than the others, you have your answer.

I had a similar problem, cases would go far enough into the chamber for the disconnecter to to unlock but the bolt wasn’t closed completely and the firing pin barely touched the primers. Cases weren’t completely sized, I could see where the bottom of the neck was stopping them from going in the chamber.

I would be suspect if somehow tools or yourself doing it at different times with a different primers? that the Winchester primer somehow come out not fully seated. do the Winchester primers fire on the second or third attempt? without knowing exactly how all the different cases were ran at the same time or not and I'll just throw it in the same box it's hard to say

The "tiniest little dimple" is probably from being chambered, not from the hammer hitting the firing pin.

incorrectly sized ammo would be my thought. OR filthy chamber. Not allowing bolt to totally close but for the pin to dimple a bit.

I think it’s the dimension on the Winchester primers. It’s all the same full length sized federal brass. I tried shooting them in a 5.56 bolt gun too. Same thing.

Have never seen that issue, but doesn't mean you aren't correct.

The word federal brass, in 223 basically meant junk. At least years ago. LC made by federal contract is different but stamped LC as far as I know.

We would trade FC for scrap or once fired LC. Or if loading it, only one firing or at least 1-2 grains less than any other brass.

It was super soft. Wonder if its not a deep primer pocket federal issue rather than a primer issue? Your finger should tell you if they feel seated deeper than others... that would be a prime indication.

oh yeah, rost ur on to something

primers not seated all the way will do the same thing. would there by any chance be a crimp on the primer pockets?

They were all swaged.

Winchester primers have never been considered hard or thick cupped.

Federal brass has generally been soft.

I would be looking at headspace. If you bumped the shoulder back too far (softer brass) then that could be the issue. Get a gauge and measure a fired case against the cases that didn’t go off.
https://www.hornady.com/headspace-bushings#!/

WW used to have hard primers. When they were silver. After they took the nickel coating off they were soft and gave slam fires in the AR and we never bought another one.

Brass WWSR should be plenty sensitive to go off.

I agree headspace IE bolt never closes all the way is likely the culprit.

Especially since the pockets were swaged and not reamed. Incorrect reaming can deepen the pockets and an aggressive seating could seat them fairly deep. Though I doubt too deep to go off.