New builder first build woes

[PistolaPadre495]

Apparently jumped into the deep end first off. Got an 80% DPMS from 5D and it milled out just fine, but no matching uppers available. Got a slick sided upper (no forward assist) from Next Level arms and it mates with barely a wiggle and a hairline gap. I assembled the upper with a 20” Ballistic Advantage heavy profile barrel with a rifle length gas port, Seekins Precision adjustable gas block, AeroPrecision gas tube and torqued the barrel to 50 lbs after lapping the upper. The bcg is AeroPrecision machined for forward assist and the buffer and spring are Luth-AR AR rifle buffer and spring in an A2 rifle buffer extension tube. It fires and ejects TulAmmo .308 150grain with no problems but hangs up when attempting to feed from the magazine, sometimes from bolt hold open and always when attempting to cycle after firing. I’m at a loss in what to remedy, but am learning that the fitment of upper and lower should probably be better. Should I go looking for a Next Level arms lower or try and wait out for 5D upper? Also what other steps do I need to take to get this rifle to be what it can?

[Tgraves3]

Where/how is it hanging up? Pictures?

[Tgraves3]

From what you have described, it sounds to me like you need to adjust your gas block to allow more gas to come in. 

[shooterrex]

BCG should be dripping wet w/lube.

Get some brass cased ammo. Steel is not your friend.

Open gas block all the way open then close down a bit at a time till it doesn't lock back on an empty mag then open back up just a bit.

Pictures would help.

[PistolaPadre495]

Tried to get pictures by cycling manually, but of course you take the vehicle to the mechanic and it stops doing the thing you’re looking for 

[Rsquared]

Welcome from Maryland.

[Cunuckgaucho]

Welcome from BC

[unforgiven]

Welcome from Indiana brother

[jtallen83]

Welcome from Iowa!

[98Z5V]

On 12/13/2021 at 10:02 AM, PistolaPadre495 said:

Apparently jumped into the deep end first off. Got an 80% DPMS from 5D and it milled out just fine, but no matching uppers available. Got a slick sided upper (no forward assist) from Next Level arms and it mates with barely a wiggle and a hairline gap. I assembled the upper with a 20” Ballistic Advantage heavy profile barrel with a rifle length gas port, Seekins Precision adjustable gas block, AeroPrecision gas tube and torqued the barrel to 50 lbs after lapping the upper. The bcg is AeroPrecision machined for forward assist and the buffer and spring are Luth-AR AR rifle buffer and spring in an A2 rifle buffer extension tube. It fires and ejects TulAmmo .308 150grain with no problems but hangs up when attempting to feed from the magazine, sometimes from bolt hold open and always when attempting to cycle after firing. I’m at a loss in what to remedy, but am learning that the fitment of upper and lower should probably be better. Should I go looking for a Next Level arms lower or try and wait out for 5D upper? Also what other steps do I need to take to get this rifle to be what it can?

Absolutely zero mention of your recoil system details - just parts (Luth).  Solve the basics first.  The recoil system and the gas system need to be balanced, and work.  Spec out your recoil system, list the details.  Rifle or Carbine, but INTERNAL DEPTH of your receiver extension.  Nobody cares how long it is, overall, and that doesn't matter in any way.  Internal Depth is the important part.  Buffer length and weight, spring length (relaxed) with coil count and wire diameter.

Next, your gas port in the barrel needs to be between 0.093"~0.096" in diameter.  That's worth looking at.  Next is gas tube length - the gas tube should (in a perfect world) end directly in the center of the cam pin cutout in the upper receiver.  Here's a thread to read, on the basics of operation.  The very first pic in the thread is perfect gas tube length:

 

Edited December 16, 2021 by 98Z5V

[AzRon]

Welcome from Arizona!