Light Primer Strikes - advice?

[Perplexed]

I have an AR chambered for 5.45x39, and I have some milsurp ammo in that caliber. As with much milsurp ammo, the primers seem to require harder strikes before they'll ignite; one out of every ten or fifteen rounds through my AR will experience a light strike but no ignition. Rechambering the round will usually result in ignition. So I figure I might need a stronger hammer spring or a lighter hammer.

Here's the problem. At present, the AR has a Geissele S3G trigger group, which I really like for the light trigger and short reset, so I'd like to keep that if possible. What can I do to alleviate the light strikes without losing the trigger feel?

 

[JamesP82]

Have you checked the firing pin to rule out issues there? My 3G has lit every 7.62 surplus I've ran through it.

 

[grwd]

You need milspec springs to light that ammo. geisele needs to go if you want reliability

 

[Perplexed]

I did check the firing pin, and it looked good. If I have to use milspec springs, can they be fitted to the Geissele, or do I have to remove the whole assembly? If the latter, what would be recommended for a milspec setup with a good trigger feel and reset?

 

[okietom]

Contact Geissele and see if you can get a stronger hammer spring from them. Or sell the rest of that ammo and get different ammo.

 

[Perplexed]

Contact Geissele and see if you can get a stronger hammer spring from them. Or sell the rest of that ammo and get different ammo.

I just might contact Geissele - how's their customer service? As for the ammo, its cheapness was exactly why I got into that caliber several years ago rather than go with commercial stuff or the 2-4X more expensive 5.56. So selling the ammo is not an option

 

[uncle money bags]

I have an AR chambered for 5.45x39, and I have some milsurp ammo in that caliber. As with much milsurp ammo, the primers seem to require harder strikes before they'll ignite; one out of every ten or fifteen rounds through my AR will experience a light strike but no ignition. Rechambering the round will usually result in ignition. So I figure I might need a stronger hammer spring or a lighter hammer.

Here's the problem. At present, the AR has a Geissele S3G trigger group, which I really like for the light trigger and short reset, so I'd like to keep that if possible. What can I do to alleviate the light strikes without losing the trigger feel?

Have you used this gun successfully with a standard fire control group?
It would be very unusual for any Giessele FCG to give light strikes and I would suspect something else unless you have narrowed it down to that variable only.
If it does turn out to be a Geissele problem, I can say their CS is top notch.

 

[Perplexed]

Have you used this gun successfully with a standard fire control group?
It would be very unusual for any Giessele FCG to give light strikes and I would suspect something else unless you have narrowed it down to that variable only.
If it does turn out to be a Geissele problem, I can say their CS is top notch.

I've tried the standard FCG with a 5.56 upper with no issues, but I was using commercial ammo, not milsurp.

However, I had an interesting exchange of emails yesterday afternoon and this morning with an assistant shop manager at Geissele; he told me that the springs in the S3G setup are full power and stronger than a mil-spec spring. He went on to say that the S3G setup is prone to bump-firing and short stroking which can result in light primer strikes, so it's critical to have the stock firmly shouldered, the trigger pulled positively with no feathering, and the pistol grip held tightly. I'll need not to finesse the trigger pull and to experiment with different stances and grips, apparently. However, wouldn't a very strong hammer spring result in a higher likelihood of the hammer following the bolt carrier?

 

[uncle money bags]

I've tried the standard FCG with a 5.56 upper with no issues, but I was using commercial ammo, not milsurp.

However, I had an interesting exchange of emails yesterday afternoon and this morning with an assistant shop manager at Geissele; he told me that the springs in the S3G setup are full power and stronger than a mil-spec spring. He went on to say that the S3G setup is prone to bump-firing and short stroking which can result in light primer strikes, so it's critical to have the stock firmly shouldered, the trigger pulled positively with no feathering, and the pistol grip held tightly. I'll need not to finesse the trigger pull and to experiment with different stances and grips, apparently. However, wouldn't a very strong hammer spring result in a higher likelihood of the hammer following the bolt carrier?

Sure, a very strong hammer spring presents its own challenges, and may require some change in your shooting style. Specifically, with weak ammo or unstable gun handling, you could experience short strokes, but they would have to be really short to cause a disco to not grab the hammer. As far as the bump fire problem, proper follow through with the trigger eliminates that.
The better your fcg is the more you have to pay attention to the fundamentals because the price you pay for that short reset precision trigger is less tolerance for non ideal shooting habits. Im using "you" in the general sense, not specifically you as a person, btw.! I have an ssa, and have been guilty of sending 2 when i meant to send 1 because i "feathered" the trigger.

 

[Honeybee]

I had a customer bring in a gun with a red tag attached by the range, said he could not shoot it again without having it checked out because it went full auto, Turned out to be his high dollar trigger.
"Feathering?" maybe for a shot or two but this thing went full auto and he could have lost his gun and have lots of legal troubles if the range had pressed the issue.