I got 2 lowers.....Noveske Gen 2 and a Aero Precision. I'm planning to pair my Noveske with a VLTOR MUR as they seem to be more of a better fit. Can anyone recommend a good upper to fit with a aero lower? Any thoughts would be appreciated. I'm open to anyone's ideas.

Accuwedge thingamajig.  I used it on my rattling Bushmaster lower and BCM upper, takes away that slight mismatch.

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I have a PSA upper on my aero lower, my RF,  and core15 uppers fit too.

maybe should list uppers that don't fit

I read that Aero lowers have a tensioning screw.
Regardless. Upper and lower fitting doesnt have much impact on accuracy. AMU did tests. So have other orgs

My Aero Precision lower doesn't have a tension screw, but I bought it a while ago.  Maybe newer ones have it.

That said, as long as the upper fit on the lower (pins can close) and function, it's good for me. My LMT upper and lower fit so tightly that I need to use a punch to start the rear pin moving.

No personal experience with the Accuwedge thing, but I've heard many reports of the thing cracking and the piece that stays in the lower can end up in the trigger group and lock it up.

My Aero Precision lowers have a nylon tipped tensioning screw.  Just be sure to set the tension before you install your grip, since the screw is located underneath it.

My Aero Precision lowers have a nylon tipped tensioning screw.  Just be sure to set the tension before you install your grip, since the screw is located underneath it.

Ahh.  It seems like the Gen 2 versions have the tensioning screw.  Interesting. 

From a quick search, it seems like the Gen 2 started coming out in the late 2014 to early 2015 time frame.  I'd have to check the registration, but I think I bought it in late 2012. 

you can do this


or drill and tap the lower for the screw.

Basically, besides billet uppers, all uppers are made by a few companies, who forge them and sell them to the distributors your probably more familiar with (spikes, aero, DPMS, RRA, etc.). The original factories that make the forgings mark them with a raised symbol. I know there's square, keyhole, a split A, and anchor marked uppers, but I think there's one or two more out there that aren't as common.  If you search Google for "upper receiver forging marks" you'll get pictures of what I'm talking about. There's also a few threads on AR15.com about who makes which, which has the best fit, and people's preferences.

I have 1 or 2 guns with aero lowers back home on the mainland. I'm 100% certain all my rifles are square or keyhole marked, and I'm only fairly certain that my aero lowers are paired with keyhole uppers. I can tell you that DPMS lowers havea little wiggle room with square marked uppers, because my rifle that has that combo uses an accuwedge. It's also my first parts built AR and has more rounds though it than all my other guns. I've had it since 2008, and I haven't had problems with the original accuwedge that I put in.

You don't actually need an accuwedge, just something to keep the slack out of the fit of the upper and lower receiver. I've heard of guys using earplugs and cigarette butts in place of an accuwedge, or even putting o-rings or other homemade shims (made from soda can aluminum) on the takedown pins if there's side-to-side play in the upper-lower lockup. But, as Ren said, there's no problem or loss of accuracy or function with a sloppy fit. Armalite even has an official letter they put out about it:
http://www.deltagearinc.com/FYI/Myths/TechNote55-ReceiverTightness.pdf

Another rifle of mine has a GPI lower and a keyhole upper and has great lockup...but has other problems. Don't buy a 300 blackout with a carbine gas system, especially with a no name, unmarked, gun broker on sale special el cheapo barrel just because it's so cheap. And don't take it to your farmer brother's workshop to open up the gas port on his 110 year old drill press he just bought for the price of scrap iron at the junkyard...and definitely don't try and use Walmart drill bits...and don't try to run high alloy lead subsonics for armadillo hunting... Yea, lots of stuff went wrong with that rifle...

Another rifle of mine has a GPI lower and a keyhole upper and has great lockup...but has other problems. Don't buy a 300 blackout with a carbine gas system, especially with a no name, unmarked, gun broker on sale special el cheapo barrel just because it's so cheap. And don't take it to your farmer brother's workshop to open up the gas port on his 110 year old drill press he just bought for the price of scrap iron at the junkyard...and definitely don't try and use Walmart drill bits...and don't try to run high alloy lead subsonics for armadillo hunting... Yea, lots of stuff went wrong with that rifle...

Now THIS sounds like an interesting story!   

Not that I would have direct experience, but I have heard the those polymer lowers are rather tight fitting and need some TLC to smoothly mate.

What may result is a supremely tight fitting upper to lower fit. 

Said to take some care and careful removal of lower material, like less than .001".  But l hear the result is like a match fit of perfectly mated parts.  No o-rings or tensioner voodoo............

The last 2 Rifles I built were...

Spikes Upper/Lower = Kinda loose

Noveske CS Gen1/BCM Upper = Tight

It's a crapshoot.  As others have mentioned I don't notice it shooting, just when handling it.

Great luck with Anderson lowers paired with PSA uppers.  No play at all