Chuck em. mtmuley
I thought it was the gun I was using. I have only had one with my other rifle not go off. Im not positive that there is moisture in them all i know is I've had some duds. I am going to do some more checking on other possibilities before I toss them since I have like 8000. I have had them in my attached garage so the moisture would just be from the air.
So when I originally looked at the range I thought it looked like a good strick but I just compared it to one that went off and it looks a little light. Left one went off right one didn't.
I will say that the two guns used were Bergara MG Micro Lite's. I had lots of issues with the first one I had in 6.5 PRC (more than rounds not going off). And I got a replacement gun in .308 and have had about dozen not go off. I have loaded about 300 in my wife's 6.5 Creedmoor and have had no issues. I wonder if Bergara has a flaw in their Premier action firing pins?
I have done that once about 2 months ago when my suspicion was the bolt. I may see if I can't find a replacement spring that's a tad stronger and see if it fixes the problem.
These really look like light strikes. My first guess is seating inconsistencies. I had plenty of these when I first started hand loading. Forget "precision" primer seaters. All cases can have different primer pockets. Especially if you get too aggressive cleaning primer pockets. Old carbon in a primer pocket means nothing as long as the vent hole is clear and the primer seats. We should all learn to seat primers by feel. Speer #10 says a primer should be about .006" below the base of the case. With experience you can feel when it bottoms out.
Brass FL over sized with too much headspace can do EXACTLY this. The shoulder moves forward reducing firing pin energy strike on the primer. Do you measure fired brass headspace to insure ONLY 0.002-0.003 setback of shoulder? I would evaluate this load step first. This is a very normal oops. I have shot primers soaked in WD40 for a week as my own personal test, they ALL went bang no problem.
Great answer.
Measuring the brass, while helpful, does not do anything to show you how it fits the chamber in your rifle other than how much your dies change from fired, to sized. Its strictly a comparative number. What you are after, especially in a hunting rifle, is reloaded ammo that fits the chamber without any resistance, every time, but is sized just enough to not create an excess headspace that will allow your ammo to move under the impact force created by the firing pin momentum. Factory chambers are usually on the high side of headspace already, just to ensure all standard spec factory ammo will fit. So, even just a couple of thousandths will have an impact on how your reloads will chamber. That's why I say, adjust using the bolt and trial fitting and not just relying on measurements of fired vs sized brass.
