Been meaning to post this for a while. I got a new upper receiver a while back, after I got the rifle back together it was off to the range to re-zero the BUIS.
I first put 10 un-aimed rounds through it to test, then took aim at paper I put up @ 25 yards; I had put a quarter in the center of the paper to use as my POA. This was the first shot, from a sandbag:
That was easy! New upper, same BUIS, no re-zeroing needed.
I first put 10 un-aimed rounds through it to test, then took aim at paper I put up @ 25 yards; I had put a quarter in the center of the paper to use as my POA. This was the first shot, from a sandbag:

That was easy! New upper, same BUIS, no re-zeroing needed.