Ar 15 issues. Dead trigger and I’m not talking about Roy’s horse Trigger

[MSAA Personal]

OK basic question on an AR I’m not having luck on the second shot
first round fires,ejects spent round, and re loads.... but no trigger pull. It’s dead?????

 

[Allsmiles]

Backwards hammer spring?

 

[MegaFan]

So, what do you do to get it to fire another "first" round? Is it a standard Mil-spec trigger? As stated above, probably hammer spring not installed properly with legs in the trigger pin grooves. Definitely sounds like FCG issues so I would pull the tigger group and start there. Seems like buffer system is working as it should with feed, initial fire, ejection, and second round pickup. Remove the upper, spend time analyzing the trigger group, and check fire, reset, and safety functions.

 

[jeep78]

Fire control group not installed right. Disconnector spring up side down, trigger spring wrong, or hammer spring on backward (as mentioned).

 

[Hayata]

What's the history on the rifle?

Trade, first build, bought new from a gun store?

 

[lilgreg46]

Dose it act normal with out ammo? No ammo pull trigger and hold. Pull chars handle and do you get a reset and hammer drop? If so load one round and see if it lock back on empty mag.

 

[MSAA Personal]

Its a colt 6933 SBR lower and colt 9mm 10.5" upper (Im using the MEAN Magpull mag conversion)
I have replaced the buffer spring with a Wolf HP and also purchased a KAW 7.5 & 10 oz buffer weights.
I have tried both buffer weights, even the original colt H buffer with and with out suppressor
shooting 115 gr and 147gr and trigger does not seem to re set.

My next plan is to try shooting with the Colt original H buffer & spring and see
then try the 7.5 oz & 10 if necessary

dry firing everything cycles as it should (with any combination), BUT Im pulling back the charging handle and not the gasses.

I think the Wolf HP spring is too stiff for the trigger to reset even with the Colt H buffer weight.??????

 

[Allsmiles]

I run a 308 carbine spring and 8oz buffer in mine without any issues. Could your bolt not be cut for a standard hammer? Seems like I saw somewhere that some 9mm guns used a different hammer. Does the lower work on other uppers?