New AR build, light strikes?

[Al-Jim19]

Took my new AR out this morning. Radical firearms upper, new frontier lower, ds arms bolt carrier, DPMS lpk. Went pretty well, fired 70 el cheapo tulammo steel cases rounds. Of those, 4 failed to go off. Wondering what the deal is - are they more likely hard primers from the Russian steel cased junk or light strikes? Each had a dented primer but it didn't look quite as deep as the rounds that went off.

If if it is a light strike issue, how might I correct that?

 

[mikelawtown]

Took my new AR out this morning. Radical firearms upper, new frontier lower, ds arms bolt carrier, DPMS lpk. Went pretty well, fired 70 el cheapo tulammo steel cases rounds. Of those, 4 failed to go off. Wondering what the deal is - are they more likely hard primers from the Russian steel cased junk or light strikes? Each had a dented primer but it didn't look quite as deep as the rounds that went off.

If if it is a light strike issue, how might I correct that?

check 1st---->

 

[slap shot]

I try different ammo before doing too much trouble shooting? If it's your first build, make sure all the springs, pins, detents from the LPK are in correctly. 4 out of 70 says that the gun is working to me. Maybe it's the ammo. Lube it up and run a couple hundred.

 

[sbi]

Took my new AR out this morning. Radical firearms upper, new frontier lower, ds arms bolt carrier, DPMS lpk. Went pretty well, fired 70 el cheapo tulammo steel cases rounds. Of those, 4 failed to go off. Wondering what the deal is - are they more likely hard primers from the Russian steel cased junk or light strikes? Each had a dented primer but it didn't look quite as deep as the rounds that went off.

If if it is a light strike issue, how might I correct that?

check 1st---->

If you experienced also a trigger spring come loose, it might be another indication of hammer spring reversed, as posted by @mikelawtown above. Ask me how I know.

 

[northny]

There has been a few threads lately on new builds (including mine) where various problem appears to have been just attributable to a new rifle that needed to be broken in. Clean it and lube it and I would bet the issue goes away.

Good luck!

 

[Al-Jim19]

Thanks guys! 70 rounds really isn't much. I'll put a few more through before I start doing much troubleshooting.

 

[SIGPRO 226]

check 1st---->

This!

 

[Drix]

I too range tested my first AR with tulammo. I fired 80 rounds, and ended up with 12 "light strikes".

I have not shot tulammo since, and I have not experienced a ftf since either. My AR now survives on a diet of soley American Eagle, which is ever so slightly more expensive, and still notoriously crap.

 

[Mark from MA]

If you didn't take apart and clean/ lube/Degrease the Bolt Carrier Group it may be that . I like to just use a light oil or CLP. Some companies grease them heavily for storage and that can be too sticky for the initial shooting runs. Other than that it usually just needs to be fired and parts need to break in.

I'd break everything down run new ammo and shoot at least 250 rounds before even giving reliability a thought. The steel case cheap ammo is prone to light strikes and cheap ass shitty primers too.

 

[jron]

Definitely double check your hammer spring, I put it on backwards on my first build and would fire a few rounds ok that FTF with light primer strike. It very well could have been the ammo, Steel stuff has hard primers and is often not the most consistently produced ammo. Try out brass after you check the hammer

 

[whalerman69]

check 1st---->

+1 Did that my first build

 

[mac1911]

If you didn't take apart and clean/ lube/Degrease the Bolt Carrier Group it may be that . I like to just use a light oil or CLP. Some companies grease them heavily for storage and that can be too sticky for the initial shooting runs. Other than that it usually just needs to be fired and parts need to break in.

I'd break everything down run new ammo and shoot at least 250 rounds before even giving reliability a thought. The steel case cheap ammo is prone to light strikes and cheap ass shitty primers too.

This, the anti corrosion film on manufactured parts is far from lube. It gets gummed up easily.
I would do a complete detail clean. Inspect all parts for correct fit and look for any wear marks .
A good working in spec AR should eat up wolf ammo with out issues.
I will gander M193/855 NATO ammo has a slightly harder to ignite primer compound and thick cup than any of the inexpensive steel stuff.
Wolf primers dedicated for 5.56 are only a different primer compound from what I have been led to believe.
I use wolf primers in all my reloading and yet to have one not go off. My stag carbine model 2 was fed exclusive diet of the cheapest steel cased Crap I could find....3k plus rounds before a proper cleaning.

 

[Al-Jim19]

Disassembled the bcg prior to firing, gave it a light coating of clp. I'll check the trigger spring!

 

[slap shot]

Come to think of it, that crap ammo is the only stuff my bump fire chokes on.

 

[mikelawtown]

My bud uses Tula in his AR 99% of the time with zero issues .

 

[ScottS]

Disassembled the bcg prior to firing, gave it a light coating of clp. I'll check the trigger spring!

Hammer spring.

 

[Al-Jim19]

Hammer spring.

Can you tell it's the first one I've tinkered with?

 

[ScottS]

Can you tell it's the first one I've tinkered with?

Between the dozen or so ARs I've built, and the hammer/trigger sets I've replaced, I've probably dropped 40-50 trigger sets into ARs.

In the middle of my work area I have a big picture of the hammer with the spring correctly installed, prominently displayed. I still look at it every time.