Light primer strikes

[Mosinowner]

I keep getting light primer with my home built AR. The ammo I'm using is PMC bronze. Suggestions?

 

[sloughfoot]

Too light hammer spring with a single stage trigger?

It is why I like to use a two stage trigger with an extra power hammer spring. It does not change pull weight and reduces lock time as well.

 

[MickeyBlueEyes]

You might have a bad firing pin also. The firing pins have a minimum protrusion length from the bolt face. You might want to check the protrusion distance. It cna cause a light primer strike when it starts wearing down.

The standard white metal firing pin wears down, and the titanium one wears down too, just at a slower rate.

 

[mike8170]

I don't want to jam on your competence, but make sure your hammer spring isn't backwards. This could easily be the problem.

 

[Mosinowner]

I don't want to jam on your competence, but make sure your hammer spring isn't backwards. This could easily be the problem.

I built the rifle and the entire time it was backwards!

 

[mike8170]

I built the rifle and the entire time it was backwards!

Thats OK, I have seen it happen to others, and I am sure I will see it happen again. I bet that trigger felt good though!

Good thing the zombie hordes didn't attack.

 

[Mosinowner]

Thats OK, I have seen it happen to others, and I am sure I will see it happen again. I bet that trigger felt good though!

Well after my trigger pin was ejected outside of the receiver it was very light. Not very crisp though.

 

[sloughfoot]

The simplest things, sometimes, at least in retrospect.....

Range report will be coming after you get the spring in properly?

 

[Mosinowner]

The simplest things, sometimes, at least in retrospect.....

Range report will be coming after you get the spring in properly?

Yep. I disassembled the rifle after I shot it the first time and must have put the hammer spring in the wrong way. This didn't happen the first time.

 

[brandonq2]

Yep, my rifle I just finished was the biggest dissapointment I could have expected on it's first range trip. I had light primer strikes on almost half of the rounds (ss109, federal fmj, and tula). Took it home, cleaned it inside and out, mic'd the firing pin and protrusion (used m16 bolt) and double checked everything without finding a problem. I've since put another 150 rounds through it without a single hiccup.

Just reviewed some photos I took the day I got it all put together, and sure enought the hammer spring was in backwards. Sadly that was the best news I could have gotten, since at least I know the gun is mechanically sound now. That seems to be the #1 cause of light primer strikes from all the research I have done. Worst part is, I'm an A.S.E. Certified master automobile technician.

Lesson learned: don't build a firearm in a hurry on your lunch break!