New AR build will not cycle open

Update

Got off work early to hit the range.

Gas block on properly and open 4.5 rotations.

https://photos.app.goo.gl/tQobpjTpHvKxMyfMA

It was ejecting the rounds at the 4 o’clock position. Even when I adjusted it to eject at the 5 it was still only opening 3/4 of the way.

Measured the port of the barrel and it measures give or take .095”

I’m using 223 feredal brass with 55gr bullets @20.8 grains of H335 (the minimum for 2800FPS)

Spoke to MRA and asked some questions. He mentioned it could be that i’m under powering it. He also mentioned to try a carbine buffer (3oz) vs 3.8 H1.

I’m sure getting closer. I did adjust the gas block a ton at the range as far as position on the barrel. That’s the best I could get.

Thoughts?
 
8bolts said:
Remove the spring pin on the buffer and remove a steel weight
Click to expand...

Do as this guy says and remove weights from the buffer one at a time testing after each weight is removed. The heavy buffer "might" be slowing the low mass carrier down too much. Removing weights is a simple way of testing for this without spending $$ on a new buffer that may not solve the problem.

You can even run the buffer empty if necessary. Contrary to what some people think, the weights aren't a necessity for function. Their primary purpose is to reduce/eliminate bolt bounce in full auto or burst. Something that you won't notice with a semi auto.

A correctly set up gas system is in 99% of cases more important than a couple decimal points worth of buffer weight difference.

Just my .02
 
Helka said:
Got off work early to hit the range.

Gas block on properly and open 4.5 rotations.

https://photos.app.goo.gl/tQobpjTpHvKxMyfMA

It was ejecting the rounds at the 4 o’clock position. Even when I adjusted it to eject at the 5 it was still only opening 3/4 of the way.

Measured the port of the barrel and it measures give or take .095”

I’m using 223 feredal brass with 55gr bullets @20.8 grains of H335 (the minimum for 2800FPS)

Spoke to MRA and asked some questions. He mentioned it could be that i’m under powering it. He also mentioned to try a carbine buffer (3oz) vs 3.8 H1.

I’m sure getting closer. I did adjust the gas block a ton at the range as far as position on the barrel. That’s the best I could get.

Thoughts?
Click to expand...

Looking at some reloading data with H335, you are undercharge on your handloads.
 
Helka said:
On route to range with factory ammo. Will update shortly
Click to expand...

I'm ashamed at myself that I didn't ask what ammo you were running right off the bat.........

.......we could have saved a lot of time lol

9 times out of then when someone's new AR15 isn't working and they're running reloads.........the gun isn't the problem ;)
 
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