Aero barrel nut enhanced handguard setup

Feb 20, 2017
Probably ordering the 15" mlok with the barrel nut to replace the cheap PSA one I over torqued and cracked on my 18" upper. Anybody have experience with this setup on a standard upper (installing the aero barrel nut and what not)?


I can use measuring things
Apr 28, 2017
San Francisco, CA
Shims on Aero enhanced? I’ve set up a few, and they didn’t come with shims. I thought that was the point. The nut is below the port for the gas tube, so you just torque it down, but on the M4E1 there’s a special wrench so don’t forget to buy that). You do have to use their hand guards, though, but that’s ok with me. In my experience, they take about 15 minutes to set up, and they shoot great. Not fiddling about with shims/timing is wonderful. The only reason I’ve bought anything else is to have a particular setup (Daniel Defense and KAC).


Sergeant of the Hide
Jan 15, 2014
Cedar Springs, MI
If it's a "standard" Upper M4E1 (not enhanced) then shims as needed. The "M4E1 Enhanced" has female threads on the upper and a large flared receiver that barrel extension slides into. No shims required for that upper because the handguard mountain directly to the upper with 8 Torx screws.

The standard upper looks like every other normal upper and handguard bolts to the barrel nut after it's installed.
Likes: jLorenzo
Feb 20, 2017
Cool just wondering if it's worth going this route as opposed to something like a standard Midwest industries on my 18" SPR, my only worry is I want to try a technique to tune the gun that involves try different torque settings on the barrel nut, shooting known lots and finding a sweet spot.If the gas tube whole in the nut doesn't line up at the sweet spot torque wise I suppose I could get it close with the shims. But that may not make much of a difference anyway.
Has anyone else had problems with a standard handguard with the 2 bottom tension bolts coming loose? Mine did, then I blue loctited it but then over torqued and pulled the bolts through the soft aluminum. PSA say they will replace it but I have to ship the entire upper back to them (on their dime at least, but will be without the gun for a few weeks)


Sergeant of the Hide
Feb 13, 2017
Peoria, IL
On a standard upper, make sure they ship the shims... If they don't file a ticket and they will get them sent to you. I installed one on a coworker's DPMS upper. It was just over upper torque limit with the few shims they sent me, but I was called incompetent when I told them they didn't send enough for proper torque. I recommend buying extra shims from the start if you want to fine tune your torque on the nut.

It will either work great, or work fine after you crank on it. I actually liked using it in the end.