AR Failure to Feed - Please Read

[Hawk]

If I understand your issue correctly your AR will not strip the first round (on a full mag) completely off the mag when you manually drop the bolt. It feeds fine on the remaining rounds.
The rifle is new?
The mag's (all of them) are new? Same brand mag's?
You're loading them each time with 30 rounds?
Brass or Steel cased ammo?
What happens if you load just a few rounds in the mag and try dropping the bolt?

I suspect it's just the new mag's. Try loading the mag's 1-2 rounds shy of 30 rounds and see what happens.
It could also be excessive resistance on bolt travel. Sometimes the bolt assembly needs a break-in period before they run smoothly.

Let us know.

[MEK1911]

If you have an other complete AR. Switch out complete uppers and lowers without switching anything else repeat your first round strip and see if the problem follows the upper or lower.

[Bang]

Lube. Per chart.

[TetsuFury508]

Now that you say it - I am almost positive its 18"

[TetsuFury508]

Gun is not new - about three or four years old - mags are all the same, I shoot the steel mags, and this error occurs with either brass or steel rounds. I really think its just the buffer tube/weight/spring setup that I have.

For the money, I am almost leaning toward just throwing a heavier spring in it and seeing what happens.

[dkf]

I am not seeing how going to a to an extra power buffer spring will fix the issue you are having. What buffer tube length and buffer weight are you currently running in the lower?

[TetsuFury508]

Whatever came with the Brownells/Midway name brand package - didnt really check it. I am running an 18" barrel and had thought that I had this setup for mid-length. So I bought the "mid-length package". I didn't want to go carbine or rifle.

My thoughts are that if the BCG, in the locked position, does not have enough force to strip the first shell from a mag - then a heavier spring will add additional potential energy to the BCG; thus giving it more force to strip that shell when I drop the bolt.

Reason being, it strips the rest of the shells just fine with no issues. But that is assisted by the gas blow back. My issue isn't with the rifle cycling, its just with the bolt dropping on the first round.

[danhr]

Does the magazine lock back on an empty magazine?

[TetsuFury508]

Yes, locks back on the final round. No issues.

[danhr]

are you running a fixed stock or collapsible stock?

a fixed stock spring is different than a collapsible stock spring. Running the wrong spring, will give you the problems that you are encountering.

edit:
Rifle Spring should measure 11 3/8" min - 13 1/2"
Carbine Spring should measure 10 1/16" - 11 1/4"