This is my first build and I went with an Aero Precision upper already cerakoted, and an Aero Precision lower, just anodized black(color to match upper not available that I see). I just got them yesterday and was checking them out. They seem awfully tight. Like squeeze hard to get them to got together kind of tight. I'd like to get the lower done professionally to match but now I'm freaking out that assembling this thing will be a nightmare now. Anyone have some wisdom to share on this matter please? Almost have all the pieces at this point and I can't wait to start. Thanks everyone!

My local gunsmith also does a lot of cerakote work and I've seen plenty of AR Uppers and Lowers done by him and all look good.  Never heard any of his customers complain about the tiight fit.  I have two Aero Precision based lowers and an Aero Precision upper I building now.  I really like their products and I'm sure you will too.

Hey man. I also chose Aero for a recent build and have about the same experience. I got an upper/lower kit and they are super tight. When I put the thing together I found that the rear pivot pin would not go through without some pretty serious coercing. Everything went together fine (as far as internals) it’s just getting the upper to mate with the lower that is a pain in the ass. I've taken to dremeling the sticking point to try and help things. Still love the look and I’d rather have it lock up tight than wobble around. Also as a side note I had a barrel cerakoted and had a hell of a time getting the gas block on. Might just be isolated to me but I’ve found that cerakote adds more material then people give it credit for. I try to keep that in mind on future builds.

I bought a cerakoted upper and regular black lower from Aero and I've got a slight bit of wobble between upper and lower.
Mine was very easy to put together but I dont think you'll have a problem that a bit of sandpaper wouldnt fix.

ever hear the dirty joke about throwing a hot dog down a hallway?  A tight fit is better than a loose one.  I've had one in-spec lower that had a tight fit and required a tool to get the pins in.  After moderate use the pins didn't require a tool to attach a lower to the upper.

Bad case scenario it rubs a little cerokote off your lower.  Worst case scenario you spend five minutes with sandpaper on the tabs on the upper.  

I recently built an upper for a friend of mine and it was a Daniel Defense upper which was cerakoted in Magpul FDE to match the URX (PN 30005) I installed on it.

My LMT lower fit that Daniel Defense upper much differently from my Noveske gen2 SBR, which was snug.

Remember that they will wear on each other and will become better over time.  If it's something that really worries you, contact Aero and have them find an upper which fits your lower better, but you'll have to send it to them.

When I went to test fire, the easiest lower I had to use was my LMT, so consider that cerakote might be making it out of "spec" that you're wanting when it still might be.

Several of my uppers and lowers are tight fits, and I don't complain about it.  I enjoy having well fitted guns.

Hey back! I read on another post about sanding the cerakote away from the 10-2 position right where the gas block goes. I think they said about a quarter inch wide. Thanks a bunch for the feedback since its the same brand an all. Thanks to everyone else too! I sure do appreciate everyone's willingness to help out a noobie. This is all uncharted territory to me and I'm learning a lot.

When done properly, Cerakote will only add .001"-.002". In rare cases, some 600grit paper will take a little off. Cerakote has lubricating properties, too....It's the ceramic.

Whats wrong with you? I get excited when I find out that mine is a tight fit.

 
Nothing that some hard use would not fix. It will loosen up over time  just like any other part.


Most problems come with getting Cerakote inside the takedown pin channel.


I know that Aero upper/lower can be a tight fit. I have 2 aero uppers and 4 aero lowers, and i find that its a mix match as far as the fit goes. (tight on one, loose on the other..?)