Light Primer Strikes...

[b2dap1]

Other day at the range I had three FTF due to light primer strikes. Only time this has happened to me with this rifle. The rounds were reloads reloaded by me. I have reloaded and shot about 1,000 rounds by now with no problems. Factory ammo is also always fine. Can light primer strikes be caused by shitty reloads? Im not to worried because it was reloaded ammo but not sure where to start to trouble shoot.

Rifle: Complete BCM upper on Anderson lower with DD lower parts kit and Wilson Combat TTU-MIL trigger.

I was running the gun kinda hard just working on reloading drills for a few hours so it wasn't just a leisurely shooting day.

[Leaveammoforme]

Are you sure you're seeing light strikes and not floating firing pin dings?

If it doesn't happen with other ammo.....

Pics?

[b2dap1]

36435

[USAF1980s]

Looks like just the normal floating firing pin strike.

If you are sure the hammer dropped, then I would guess you have a bolt bounce issue.

State what type buffer and spring you are using.

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[b2dap1]

H buffer (3.8 oz) and JP polished spring.

[USAF1980s]

Did the hammer drop?

If so then if the BCG locks back on a single round, you may want to try an H2 buffer.

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[b2dap1]

Yes the hammer dropped. It does lock back.

[Leaveammoforme]

Pic looks a little heavier than standard float ding to me. I would get a case gage and start checking your reloads.

[P2000]

The strike seems stronger than an inertia strike from chambering, but it is hard to say.

Did that cartridge come out easily via pulling on the charging handle? Or did you have to mortar it / pull hard on the charging handle?
Do the primer strikes on your other spent brass look good or look weak?


This could be a primer seating issue, headspace issue or bolt bounce

[Coal Dragger]

Ensure your case dimensions are correct with a case gauge. If your case has the shoulder pushed back too far light primer strikes can occur as well as possible case head separation due to excessive headspace with that ammo.

You should also make sure the primer is fully seated in the primer pocket. If it is not the firing pin will waste a lot of energy pushing the primer into the pocket instead of igniting it.

If problems persist after these two steps, ensure your hammer spring is a full power spring. Not sure if the JP is or not.

Lastly, if issues persist even after all the above steps, try another batch of primers.

My guess is you are pushing the shoulder back too far on your cases, the photo looks like a shallow strike on the primer. Ignore the instructions to set the sizing die down until the shell holder touches it, buy a case gauge and set the die based on the gauge. If you are reloading on a progressive machine setting the resizing die via case gauge is the only way to establish proper case dimensions due to the dimensions of the shell plate.

A case gauge is relatively inexpensive, and is a great tool for checking ammo, setting dies, and spot checking brass to determine trimming intervals. They are invaluable for bottle necked cartridges.

[b2dap1]

I will check the ammo in a case guage tonight. The round came right out with charging handle. The JP spring is the buffer spring.

[Coal Dragger]

Good luck hope you get it figured out.

[b2dap1]

Thanks. Im only gonna shoot good ammo for a while and if it stops ill be good with that. Maybe its also time to clean it!

[Coal Dragger]

Yeah if there's enough carbon build up in the firing pin race way it could be an issue. Add a good cleaning to the list.

I'll bet you a Coke that setting your sizing die to spec, and ensuring your primers are fully seated will result in 100% reliable ignition.

Did you try to refire any of the rounds? If so did they ignite the second time?

[b2dap1]

yes they did fire a second time.

[Coal Dragger]

OK, that should be a good sign the primers themselves aren't defective.

There might be a possibility your hammer spring is weak, but only if it has a lot of use on it or a long storage period in the cocked position. Even then quality steel springs probably still wouldn't be weak. Plus a GI hammer and spring usually have plenty of reserve power to pop a primer.