M15 lite primer strikes

[duckloads]

About once in 50, I'm getting a lite primer strike with my M15-4. It's about a 1983 model with hammer mounted firing pin. I reload, and primer brand doesn't seem to matter. The lite strike produces a very small "dink" on the primer. I can cycle the round back through and it fires, no problem, with a normal looking dented primer.

The strain screw is tight.

Any ideas?

 

[WR Moore]

Headspace/endplay OK? Assuming that you or a previous owner didn't bend or change the mainspring or trim the strain screw, it could be operator error. It is possible, when trying to finesse a shot, to stop your trigger pull exactly when the trigger breaks which can allow (your finger may relax a wee bit after the trigger breaks) the rebound slide to brush the falling hammer and rob energy sufficient to cause light strikes. Making sure that you pull the trigger (and hold it) against the stop will prevent this issue.

 

[bountyhunter]

About once in 50, I'm getting a lite primer strike with my M15-4. It's about a 1983 model with hammer mounted firing pin. I reload, and primer brand doesn't seem to matter. The lite strike produces a very small "dink" on the primer. I can cycle the round back through and it fires, no problem, with a normal looking dented primer.

The strain screw is tight.

Any ideas?

Most of the time it is due to a primer not fully seated.

The "tiny dent" followed by a deep dent when it fires is because at ignition, pressure forces the primer face to "backflow" around the head of the firing pin so it will look deeper. Your strike force is probably the same.

 

[S&W-Keeper]

Are you using Blazer Brass ammo? I have had the same problems that you describe with their .40 cal.

 

[duckloads]

Are you using Blazer Brass ammo?

Nope, reloads.

Thanks for the suggestions. I'll pay closer attention to the whens and hows on my next trip to the range. My last trip with ONE lite strike in 50 rounds was with CCI primers. I loaded a box with Remington primers. I'll verify again whether or not the primer mfg has anything to do with lite strikes.


be safe.

 

[H Richard]

How long since the gun was completely disassembled and cleaned? Are you sure the strain screw is tight and full length? If a previous owner "shortened" the strain screw to get a lighter trigger pull, it may be a cause. Or, accumulation of residue, oil, etc. in the action, (but that would usually cause more frequent misfires). A primer not fully seated would be pushed forward and may not go off as it acts like a cushion absorbing the hammer fall. Another possible cause is a primer pocket not square at the bottom. If enough air gap the primer anvil won't reach the shell base when struck.