I have two 16" mid-length 1:7 twist uppers. When I take an Aimpoint in a LaRue mount that’s been zeroed on one of the uppers and put it on the other upper it shoots about 6-8 MOA left with no vertical POI shift, using the same ammo.
I’m just curious if this is a typical amount of variance in POI between uppers? I’m not expecting the Aimpoint to be dead on when switching between uppers, I just would have thought there’d be less of a variance between such similar uppers. The Aimpoint does return to zero when put back on the first upper.
I can QD a NXSc from one chassis(rifle)…place it on a totally different chassis(rifle), and have absolutely zero windage shift. I still have elevation shift given I’m running different barrel lengths. MRPs are freaks:p
I have a 12.5" and had a 16" middy with both using Vltor MUR receivers. My Aimpoint on a Bobro mount didn’t show any windage shift between the two. Is the 6-8" shift repeatable?
Here is the optic with a 100 yard zero from my 16". These were my first three shots at 25 yards with the brand new 12.5" upper.
Thanks for the replies everyone. I certainly wasn’t expecting the two uppers to have the exact same zero. I was just surprised that there was this much of a variance. I guess I was just expecting them to be a bit closer, but I don’t know what’s a typical amount of variance between uppers.
johnson, yes the shift is repeatable. I actually checked with both a CompM2 and T-1 and both had the same amount of shift.
How does that work technically speaking? Thats very interesting.
I was amazed that my larue mount kept a zero after removing it and replacing it on the SAME rifle.
I’m sure that a lot comes into play. I have seen a 2" shift to the left at 100yds between an LWRC and a M&P15T.
I walked away with the assumption that the two rifles would have close POI’s, but I’d be mistaken. Just curious, what kind of hand gaurds? Both were free floated in my case.
Because some of us grew up when “No Shift In Zero” when removing and re-installing QD mounts meant you were lucky if POI shift stayed in the same zip code
MOE handguards on one upper and standard plastic ones on the other, but I zeroed resting the mag on the bench to avoid any POI shift from a rest touching the handguards.
Before trying the Aimpoint on the second upper I would have guessed it’d be within about 2-3 MOA, but I didn’t really have any basis for that estimate. That’s why I was a bit surprised the zeros were so far off.
