Hi, I don't post here much, and I feel like this is a stupid question, hence posting it here.
I have an AI AT in 6.5 CM, 24" bbl. Before I went to the range today I had 765 rounds through it. It shoots well, best shooting rifle I've ever had. Each day I go out I shoot a cold bore shot at 100, then a five shot group. Then I let it cool, then shoot some dot drills, about 10 rounds. Then I head over to shoot on a longer range, 600-1000. I only shoot one or two groups each day, and they average .35-.45 MOA. Sometimes it shoots .25 MOA, and sometimes .5. This is with FGMM 140 SMK factory ammo.
I have cleaned the rifle only once, at about 450 rounds, just a minor cleaning, following Frank's advice in the online training. It just shoots well.
So today I do the same routine. After my drills I try a box of Winchester 140 Match Factory ammo, and get a .25 MOA group less then .1 mil off my zero. Then I head over and shoot at 600. I get about 20 rounds downrange on steel, hitting with the SMKs in 13 MPH Winds with about a full mil wind dialed in and holding I try some more of the Winchesters, and it shoots really well, slightly different dope, corrected by watching splash, just a few tenths of a mil offset elevation. I'm letting it cool between strings of 10 rounds.
I head down to paint my steel, and when I get back and redope for the FGMM, I 'm pretty far off my dope. I was at 4.2 mils elevation before, and 3.9 with the winchester ammo, so not a big difference. I dial it up and down just a bit, and it keep impacting about two mils up! I try dialing all the way down to 3.5, and no change in impact! I dial down to zero, then back up to 4.2, and I can't see the impact anymore. I can hear it hitting the number boards way up on the berm, so I dial down to zero, and I see an impact 2 mils above the target. At my zero I consistently see impact approx 2 mils up.
This is my second day on the range with a new Schmidt and Bender PM2 (with MTC turrets). I zeroed it yesterday, and confirmed zero today. I didn't do a tracking test, but it was a first round hit with my previous dope at 600. I check parallax. I even checked the torque on the Spuhr mount. All good. I felt like when I was downrange someone fucked with my turrets, though I'm sure that's not the case.
So I went back to 100, dialed to zero, couldn't even get on paper. At least 6 mils up. What could have caused this? When I got home I checked the RTZ screws in the turrets, they were still snug. I cleaned it, it wasn't all that fouled. I thought maybe it was the RTZ screws coming loose or something as I dialed and it moving the turrets but not changing the erector. But the screws were still snug. I mean, if it was fouling, wouldn't it slowly open up, and would it get THAT far off? I mean, it's more than six mils off at this point.
I'm stumped, ideas?
I have an AI AT in 6.5 CM, 24" bbl. Before I went to the range today I had 765 rounds through it. It shoots well, best shooting rifle I've ever had. Each day I go out I shoot a cold bore shot at 100, then a five shot group. Then I let it cool, then shoot some dot drills, about 10 rounds. Then I head over to shoot on a longer range, 600-1000. I only shoot one or two groups each day, and they average .35-.45 MOA. Sometimes it shoots .25 MOA, and sometimes .5. This is with FGMM 140 SMK factory ammo.
I have cleaned the rifle only once, at about 450 rounds, just a minor cleaning, following Frank's advice in the online training. It just shoots well.
So today I do the same routine. After my drills I try a box of Winchester 140 Match Factory ammo, and get a .25 MOA group less then .1 mil off my zero. Then I head over and shoot at 600. I get about 20 rounds downrange on steel, hitting with the SMKs in 13 MPH Winds with about a full mil wind dialed in and holding I try some more of the Winchesters, and it shoots really well, slightly different dope, corrected by watching splash, just a few tenths of a mil offset elevation. I'm letting it cool between strings of 10 rounds.
I head down to paint my steel, and when I get back and redope for the FGMM, I 'm pretty far off my dope. I was at 4.2 mils elevation before, and 3.9 with the winchester ammo, so not a big difference. I dial it up and down just a bit, and it keep impacting about two mils up! I try dialing all the way down to 3.5, and no change in impact! I dial down to zero, then back up to 4.2, and I can't see the impact anymore. I can hear it hitting the number boards way up on the berm, so I dial down to zero, and I see an impact 2 mils above the target. At my zero I consistently see impact approx 2 mils up.
This is my second day on the range with a new Schmidt and Bender PM2 (with MTC turrets). I zeroed it yesterday, and confirmed zero today. I didn't do a tracking test, but it was a first round hit with my previous dope at 600. I check parallax. I even checked the torque on the Spuhr mount. All good. I felt like when I was downrange someone fucked with my turrets, though I'm sure that's not the case.
So I went back to 100, dialed to zero, couldn't even get on paper. At least 6 mils up. What could have caused this? When I got home I checked the RTZ screws in the turrets, they were still snug. I cleaned it, it wasn't all that fouled. I thought maybe it was the RTZ screws coming loose or something as I dialed and it moving the turrets but not changing the erector. But the screws were still snug. I mean, if it was fouling, wouldn't it slowly open up, and would it get THAT far off? I mean, it's more than six mils off at this point.
I'm stumped, ideas?
