Scope swapping and zero

[P2Vaircrewman]

I have a Colt LE 6940 with an Aimpoint PRO and mount. I just bought a Burris Mtac 1 to 4 scope. I haven't yet bought a mount for it yet. I assume a one piece mount will return to zero better than a two piece mount. My question is how close a return to zero can I expect when swapping between the two optics. Aimpoint says if removed and remounted to the same position there should be very little if any shift in zero. Anyone have any experience is swapping optics and zero retention.

[GH41]

For practical purposes if both were in quality mounts the difference would be way less than the mechanical accuracy of your setups.

[IndianaBoy]

Within 200 yards, if you install both mounts correctly... less than MOA shift.

I have used Larue and ADM mounts that returned to zero. One small hint, push the mount/optic forward as you close the throw levers.

[P2Vaircrewman]

Thanks guys, that's kind of what I thought.

[MartinOwen]

everything depends on the type of mount you are using. The quality or less quality. but I will advise you to try a quick mount and disconnect rings. They are more accurate when switching between scopes.
image_15-36-12_07302_07-09-2016.jpg

[WS6]

I have a Colt LE 6940 with an Aimpoint PRO and mount. I just bought a Burris Mtac 1 to 4 scope. I haven't yet bought a mount for it yet. I assume a one piece mount will return to zero better than a two piece mount. My question is how close a return to zero can I expect when swapping between the two optics. Aimpoint says if removed and remounted to the same position there should be very little if any shift in zero. Anyone have any experience is swapping optics and zero retention.

I have used the qrp2 mount on a PRO, at 50 yards and noted no statistically relevant zero shift.
I have used the night force unimount and geissele super precision mount at 100 yards, correctly torqued, and noted the same.

[WS6]

everything depends on the type of mount you are using. The quality or less quality. but I will advise you to try a quick mount and disconnect rings. They are more accurate when switching between scopes.
image_15-36-12_07302_07-09-2016.jpg

This has not been my experience. Torque to 65 in lb mounts return to zero as well or better than the Bobro, and MI, that I have tested.

[Doc Safari]

Disclaimer: I'm a plinker that rarely shoots on paper, so my experience has an asterisk that I can't address any precision or MOA requirements.

Having said that, being a little indecisive at times, I've swapped an Aimpoint T1, Aimpoint Pro, and TA33 ACOG between a BCM carbine and a Colt 6920 carbine.

Shooting at cans up to roughly 100-150 yards, I did not have to adjust any of them between rifles, nor did I have to re-zero any of them after dismounting and remounting.

I suspect if I had conducted the swap more scientifically I might have noticed a minute shift in something, but making aluminum cans dance in the desert you wouldn't notice a dime's worth of difference in zeroing between the two rifles and I feel confident I can dismount an optic for cleaning without worrying.

[SomeOtherGuy]

Within 200 yards, if you install both mounts correctly... less than MOA shift.
I have used Larue and ADM mounts that returned to zero. One small hint, push the mount/optic forward as you close the throw levers.

I agree with this, BUT - the QRP2 mount that comes with the Aimpoint PRO is, in my personal experience, junk. They often don't stay tight, and may self-loosen enough to even fall off, of course at a bad time. Since the intended use of the mount (rotate til you hear 3 clicks) is idiot proof, I know it wasn't my technique causing this.

Using any quality lever-lock mount (ADM, Larue, Bobro, GGG) or using a properly made screw-tighten mount you should be able to get good repeatability, at least within what you expect of a 6940 and a red dot. I've had very good luck in semi-precision use with ADM mounts - zero, go home, get antsy and take the scope/mount off the rail, put it back on a month later, confirm zero and find it's still right on.

For quality mounts, basically buy American and it should be OK. Avoid Chinese and mystery origin mounts.

[Tequila45]

I swap between my t-1with larue mount and my Burris with ADM mount and notice no shift.