So, I have a Nikon Prostaff 3-9 that I have had for a few years now, only has about 200 rounds through it. Used to be on my 8mm Mauser. After sighting it in it used to hold zero and group well, but as time progressed, I would take the rifle out of the gun cabinet, and it would consistently shoot about 6 inches high, and couple inches either left or right and would need to be zeroed over again. Took it out to sight it in for deer season this year, and shots were high and all over the place at 100yds, gave up, and used my M305 with irons for hunting instead. I thought something must be loose on the rings or the gun, figured I'd get around to solving it eventually.
Well since then, I purchased a different gun, and put the Prostaff in a one piece PEPR mount and put it on the .308. Sighted it in at 25yds, everything seemed fine.
Had the scope off (QD mounts are fun!) so I sighted it in at 25 again (on 9x), it was a little high and right, no big deal, adjusted it to center and put 3 rounds through the same hole.
Moved out to 100yds, didn't change the magnification. First group was about 6 inches high, and about 3 right. Adjusted back to center, and put 2 within a half inch of each other, and the 3rd was about 3 inches high and slightly left.
Figured the last one might have been user error, moved to a different target square, fired another 3. One off paper somewhere to the left, 2nd 2in high 2inches left, 3rd 5inches high and 1/2inch right.
Said what the heck, changed targets, fired a 5 shot group. 4 were within an inch with one flyer about 2 1/2. Decent group for my (lack of) ability. BUT. They were back to being 6 inches high, and about 4 inches left.
So ultimately, it is two separate guns with different rings, the only thing being the same is the scope, and it still seems to have exactly the same result. Random shifts in points of impact climbing up to around 6 inches high.
Well since then, I purchased a different gun, and put the Prostaff in a one piece PEPR mount and put it on the .308. Sighted it in at 25yds, everything seemed fine.
Had the scope off (QD mounts are fun!) so I sighted it in at 25 again (on 9x), it was a little high and right, no big deal, adjusted it to center and put 3 rounds through the same hole.
Moved out to 100yds, didn't change the magnification. First group was about 6 inches high, and about 3 right. Adjusted back to center, and put 2 within a half inch of each other, and the 3rd was about 3 inches high and slightly left.
Figured the last one might have been user error, moved to a different target square, fired another 3. One off paper somewhere to the left, 2nd 2in high 2inches left, 3rd 5inches high and 1/2inch right.
Said what the heck, changed targets, fired a 5 shot group. 4 were within an inch with one flyer about 2 1/2. Decent group for my (lack of) ability. BUT. They were back to being 6 inches high, and about 4 inches left.
So ultimately, it is two separate guns with different rings, the only thing being the same is the scope, and it still seems to have exactly the same result. Random shifts in points of impact climbing up to around 6 inches high.
