Light Primer Strikes on Geissele SD-E + 300BLKOUT Build

[joeg26er]

Getting Light Primer Strikes on Geissele SD-E + 300BLKOUT Build / BCM 9 inch

About one or two for every 20 to 30 rounds.

I've used a standard weight BCG NiB Stag and a lightweight ALU 3Gun unit and similar ratio of light strike FTF. Will not ignite when put through a second time.

Using Sellier and Bellot 123gr. What do you think I should start trouble shooting or is this a bad batch of ammo? Or could something be wrong with my fire control group?

[Coal Dragger]

Is the hammer spring installed correctly?

[georgeib]

Is the hammer spring installed correctly?

This would be my first guess also. But you may want to check to make sure that the hammer is moving freely, and that the firing pin isn't encountering any resistance in the firing pin channel.

[titsonritz]

Is the hammer spring installed correctly?

I'd bet that is the problem 90%+ of the time.

[joeg26er]

This has happened with two different and low round count BCG's so I am pretty sure about ruling out the firing pin

I just checked the install and spring positions and they are correct.

Double Checked the FTF rounds and the firing pin mark shows about half to 2/3 the size as the spent rounds. I suppose the only other thing to try is swap out the lower to see if a different trigger is better or perhaps this hammer spring needs replacement?

[RobertTheTexan]

Getting Light Primer Strikes on Geissele SD-E + 300BLKOUT Build / BCM 9 inch

About one or two for every 20 to 30 rounds.

I've used a standard weight BCG NiB Stag and a lightweight ALU 3Gun unit and similar ratio of light strike FTF. Will not ignite when put through a second time.

Using Sellier and Bellot 123gr. What do you think I should start trouble shooting or is this a bad batch of ammo? Or could something be wrong with my fire control group?

I encountered a similar situation once when using a “light” trigger. One thing different though, my second attempt to fire did send the round down range.
But the first thing I did was pop out that mag and load up a mag of different ammo, a known good ammo, higher end ammo. The weapon fired the other ammo as it had been, which was flawlessly.
I found that I had purchased a “Lot” of ammo with hard primers.
Ran that same ammo in my LMT MWS 308 with a different trigger with zero misfires.

So my first step is to test a different ammo.


Sent from my iPhone using Tapatalk

[joeg26er]

I encountered a similar situation once when using a “light” trigger. One thing different though, my second attempt to fire did send the round down range.
But the first thing I did was pop out that mag and load up a mag of different ammo, a known good ammo, higher end ammo. The weapon fired the other ammo as it had been, which was flawlessly.
I found that I had purchased a “Lot” of ammo with hard primers.
Ran that same ammo in my LMT MWS 308 with a different trigger with zero misfires.

So my first step is to test a different ammo.


Sent from my iPhone using Tapatalk

I've tried to fire the light struck round again and they did not go off.
I think I will also order an SD-C Spring kit

[georgeib]

I've tried to fire the light struck round again and they did not go off.
I think I will also order an SD-C Spring kit

The SD-C spring kit and the SD-E both use the same hammer spring, so you won't see any difference with ignition reliability.

[joeg26er]

The SD-C spring kit and the SD-E both use the same hammer spring, so you won't see any difference with ignition reliability.

Thanks for the information
I guess it’s back to trouble shooting

[ssc]

Try a different lower with another trigger/hammer set up. If it fires, I would speculate that the hammer spring needs to be replaced. I had a GSD3G in a particular lower that started to do the same thing. A new hammer spring solved the problem. Hammer springs do wear out.

Cheers, Steve