Aero Precision M4E1 Enhanced Upper Receiver Assembly - Black

This is my 3rd enhanced upper from Aero Precision. All of my builds are sub MOA with low power (6x or less) optics at 100 yards. The entire point of this upper is to rid your build of any barrel flexure. On mil-spec builds when resting your handguard it puts stress on the barrel nut which in turn puts stress on the barrel causing a POI shift. This strengthens that weak spot significantly! The last one I bought the tolerance was so tight I had to freeze the barrel and use a hair dryer on hot on the upper to get it to fit, they've always been tight but this was machine fit tight! I wish all were this close fitting as it means no room for shifting. Great service as always from PA and AP!
<br>P.S. - bar type handguards are the best for structure support firing and maximizing air gap between your hand and a hot barrel during heavy engagement scenarios.

I purchased the Aero Precision M4E1 upper with the 15" MLOK handguard for my 20" 6.5 Grendel build and I couldn't be happier. The barrel and handguard lock-up is great, no moving parts. This is a very solid lock -up and I would highly recommend it to anyone building an AR style platform rifle.

I bought one of these in FDE to mate with a Wilson Combat Lower, talk about a match made in gun heaven. Zero jiggle or wiggle.

Very good quality. Kind of impressive really.So much better than the surplus parts I used to use. If it's worth doing.... BTW shipping was really quick. Primary Arms will be my source for new builds.

The price is right and the fit and finish are excellent. I only use Aero Precision for my builds. So far I've purchased two M4E1 uppers to use for my 300 Blackout SBRs and couldn't be happier.

but overall great productI bought this upper because I was building my first AR and it seemed like the easier option. However I didn't really notice how difficult it would be to find a handguard to fit the upper as a result. That being said this product makes swapping barrels easy as can be it saves you money and stress of finding additional parts such as the barrel nut and delta rings etc. I really wanted a magpul hand guard but you cannot use one with this upper. Your only option is a free float rail which does add some undesired weight to the front of the gun especially as you add accessories. However I am satisfied with the product it is a good price and my local gunsmith was impressed with the quality and unique design.