I finally got a chance to do something I've been wanting to for some time - test the zero shift between caliber change with the XCR and also the return to zero switching back. Unfortunately, my club had a 600 yard shoot going on, which closes the 100 and 200 yard ranges, so all I had was a 50 yard. Which actually is probably better, cuz I'm cross dominant and not a great rifle shooter.
So I started with my XCR-L in 5.56. Using a 1-6x Vortex Strike Eagle and American Eagle .223 55 grain ammo. The targets are B-29 (1/3 size of B-27 to simulate longer range at shorter range). Shot from a bench, but I only had a small bag that I had to rest my hand on top of to hold the handguard while also using the mag as a monopod.
Pretty decent for me. 3 touching for a 7/8" group. Double it to 1 3/4" for MOA at 100 yards.
Switched to the 7.62x39 kit, also using American Eagle brass (124 grain):
The one that dropped was my first, but I didn't "call it" so I don't know what's up with him. Too short of range to be a cold-bore shift I'd think. Without him, that's 1/2" at 50, 1 MOA. With him it jumps to 4 MOA. So I reshot, aiming at the low 7, just to verify and got:
Right at 1" spread for 2 MOA.
So the 5.56 shot a bit low (to be expected at 50 yards), the 7.62x39 shifted 1.5" up and 1.5" left. Not too shabby for a barrel and caliber swap. So now let's see how the return to zero is when I switch back to 5.56:
Opened up a slight bit to 1" (2 MOA), but that's likely more me than anything else. Stupid wonky eye. But returned right to original zero. Reshot at the low 7 to verify and got the same results (as you'll see below)
Can't complain one bit, obviously this is a sample size of one and doesn't necessarily apply to other XCR swaps. But I can make an adjustment cheat sheet for the inside cap.
Posted: 6/14/2020 10:22:24 PM EDT
[#1]
Like.
Posted: 6/15/2020 6:46:56 PM EDT
[#2]
Neat. I took the barrel out on my XCR-L (.223) for a deep cleaning awhile ago and didn't see any zero shift when it was re-installed. Robinson does exquisite work on these rifles, particularly the barrel shank and receiver "sleeve".
Posted: 6/16/2020 10:20:59 AM EDT
[#3]
Helpful knowledge. Thank You for sharing.
Posted: 6/16/2020 10:17:52 PM EDT
[#4]
The most shift I have seen has been about 2 moa, but that was after a good decoppering as well.
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