Vltor MUR vs Aero M4E1

[jrcii]

Hello All,

I'm gathering parts for a precision .223 build. Recently I started reading about still having a POI shift even with a free float hand guard. They're saying that because the rail interfaces with the barrel nut, pressure on the rail will put torque on the barrel nut and therefore on the barrel. I read a pretty good analysis that was showing about a 0.3 MOA shift.

When I started this project, I'd decided on a Vltor MUR and a Geissele MK8 because of the receiver's thick walls and the stiffness of the rail. But, now I'm thinking about the Aero M4E1 because the rail interfaces with the receiver instead of the barrel nut. I don't want to go with a monolithic upper, and this seems like the next best thing. The Aero combo costs about what you would pay for the Geissele rail alone, so that does kind of concern me as you get what you pay for.

So, given those two choices, which would you pick? I know that 0.3 MOA doesn't sound like much, but a semi-auto .223 is already going to be 'accuracy challenged' when compared to a bolt gun all other things being equal. So, I'd like to start with the best base possible. I'm not even sure that the POI shift is a universal thing or if it was just for that one guy. So, this whole thing may be immaterial.

I'd really appreciate your opinions on this one.

Thanks,

JRC

[C4IGrant]

Hello All,

I'm gathering parts for a precision .223 build. Recently I started reading about still having a POI shift even with a free float hand guard. They're saying that because the rail interfaces with the barrel nut, pressure on the rail will put torque on the barrel nut and therefore on the barrel. I read a pretty good analysis that was showing about a 0.3 MOA shift.

When I started this project, I'd decided on a Vltor MUR and a Geissele MK8 because of the receiver's thick walls and the stiffness of the rail. But, now I'm thinking about the Aero M4E1 because the rail interfaces with the receiver instead of the barrel nut. I don't want to go with a monolithic upper, and this seems like the next best thing. The Aero combo costs about what you would pay for the Geissele rail alone, so that does kind of concern me as you get what you pay for.

So, given those two choices, which would you pick? I know that 0.3 MOA doesn't sound like much, but a semi-auto .223 is already going to be 'accuracy challenged' when compared to a bolt gun all other things being equal. So, I'd like to start with the best base possible. I'm not even sure that the POI shift is a universal thing or if it was just for that one guy. So, this whole thing may be immaterial.

I'd really appreciate your opinions on this one.

Thanks,

JRC

I have had good experience with VLTOR products so can recommend them for sure. I have not used the AERO so I will not comment.

Another good option is the Mega billet upper receiver: http://www.gandrtactical.com/cgi-bin...n&key=M0304-HA


C4

[nova3930]

I used an Aero 8" 300BLK M4E1 upper on a rifle. The rail is only 7" but overall the thing feels super stiff. At least part of that is probably due to the 1.5" OD of the rail itself though...

[ScottW511]

I built up a shorty AR using an M4E1 10.5 upper. While it's not built as a precision rifle it shoots groups at 50 yards for zeroing just as tight as my JP VTAC. I like the design enough that I have the 308 version on order.

[RAM Engineer]

How do the Larue Stealth Uppers compare to Vltor, Mega or Aero? I prefer the clean looks of them vs most billet receivers.

[irondude]

I have a MUR Noveske upper receiver on a 20" precision build and it works as it is supposed to. I mates up well with a Noveske mil forged lower. Meaning it does not look odd like some of the billet uppers do on a forged lower. I am using a Noveske 16.7" NSR rail with a Proof Reseach Barrel. I am getting 3/4 MOA with 77 grain PRIME of Federal GGM.

[StevethePirate]

Your barrel will probably play more into the accuracy of your build more than upper receiver, as long as it's in spec. Aero will work well, but Vltor/Geissele is a step or two above, in both price and build quality.

If you'd like to save a little, BCM uppers are also built a little thicker in areas and have VERY tight receiver to barrel tolerance.

[OrbitalE]

My MUR with Geissele rail and LaRue barrel shoots sub-MOA as long as I do my part and feed it quality food.

[Eurodriver]

My MUR with Geissele rail and LaRue barrel shoots sub-MOA as long as I do my part and feed it quality food.

8" at 800 yards is pretty good!

[OrbitalE]

8" at 800 yards is pretty good!

Okay, perhaps I embellished lightly. 8" at 800 yards is beyond my shooting capability. It'll do approximately 1" groups at a 100yds until I flinch (and it is capable of .75" at that distance with BH ammo) and it'll ring steel to 600 all day which is as far as I've verified it.

I have no evidence it is more capable than any of my other rifles, but I can say it is capable for longer simply due to the barrel's thermal mass. I have not noticed deflection of the handguard either, which is present in some of weight weenie guns.