AR15 Build Issue

[strange246]

Built my AR about 2 months ago but just got a chance to shoot it, Del-Ton Dissapator upper, A2 stocked LW15 lower, magpul mag, 2 different ammo's, the first round feeds and fires fine, 2nd round gets loaded but the bolt never traveled far enough back to reset the hammer, I assume the issue is to do with the gas system being rifle length with only the 16" barrel, would a lighter buffer spring help? Perhaps a carbine length spring and buffer in the A2 buffer tube?

Thanks

 

[MachIVshooter]

2nd round gets loaded but the bolt never traveled far enough back to reset the hammer,

Not possible.

There's an issue with your secondary sear; Perhaps the spring is not installed correctly?

 

[strange246]

Hmm I'll check, this lower I bought assembled, but I suppose its not impossible to be built wrong...

 

[GI_Jared]

please post some pics of the build, this will help in the diagnosis.

 

[strange246]

Only pic I have of if right now...

 

[GI_Jared]

need to see inside the lower receiver, where the trigger assembly is.

 

[strange246]

Ah gotcha, I'll post some in the morning, I cant get to it right now...

 

[Jackal]

Your short cycling. Make sure your bolt carrier is not rubbing on an out of spec buffer tube, I had this happen once. I would retract the bolt by hand and it would stay in the buffer tube:banghead:. Also, check to see if there isnt a bur or blockage where the barrel mates with the gas block/check for a good seal/alignment.

 

[Infidel4life11]

I would say your trigger group also. Sound like your hammer isn't being caught.

 

[briansmithwins]

Yeah, if the BCG is opening enough for the fired case to be ejected, much less the next round loaded, the hammer is being cocked.

I agree that the problem is most likely the hammer following the BCG down.

BSW

 

[Ramone]

my best guess:

Disconnector spring upside down.

It's the tiny spring that sits in the trigger under the disconnector- one end of the spring is larger- that one goes 'down' (into the trigger first) so it stays in place.