Last couple range sessions as I’ve honed in on some loads and collected dope has left me scratching my head upon review. I’m trying to make sense if I have a scope issue going on or missing something in the data or what. I don’t have the best chrono so even leaving some margin of error there the inconsistencies seem far too great to tune velocity and/or BC from published data.
Range conditions depending on the day: ~24.5-25 inHg, 60-90F, low humidity.
208ELDM: published G7 0.337, velocity ~2750fps
181hammer: published G7 0.272, velocity 1: ~2900fps & velocity 2: ~2950fps (two different loads I was checking)
Last week I zero’d the 181hammer at 200 within an inch (so factor in that slight potential for error), the 208eldm was an inch or so lower but close enough of a zero I’d land on paper while checking drops. I put a target out at 1043yd for the eldm and dialed in 26MOA, landed them basically right on in terms of elevation. Brought the target in closer to catch a small charge ladder of the 181hammers (in the 2900-2950fps range) at 550yd and with 8MOA left impacts ~9” low, this seemed odd indicating a large velocity or BC variation, IF the rifle was still zero’d but I was out of test rounds.
Yesterday I start at 200 and shoot a round of the 181hammer and 208eld, they’re all low needed to come up 2MOA to zero the hammer and slightly low 208eldm. Then moved the target out to 426yd: 208eldm 11” low with 5.5MOA dialed, the 181 hammer groups were 6-7” low with 5MOA. This seems odd after just zeroing at 200yd to be that low with the given dial ups. Moved the target back to 666yd, first hammer rounds were in the dirt in front, I added 3 more MOA on the dial and caught the last 2 of each: ~2900fps group was 12.5” low with 15MOA, ~2950fps group was 9” low with 15MOA. The 208eldm was 15” low with 15MOA. None of this was looking right, I was out of hammers but had some eldm left, I moved the target back in to 200 (actually ended up at 190yd), return to zero had the elm 1.5-2” low (IE basically returned to its zero from the morning). I put a couple rounds on paper with 3MOA wondering if the clicks were notably off (should have flipped the target and did a greater dial up amount for the test) and things moved ~6”.
Generally I’m baffled. The data yesterday suggested its tracking at .79MOA/100yd BUT if that was the case there is no way I’d have landed those shots at 1043 on paper with 26MOA dialed (similarly this indicates my chrono isn’t massively out of calibration). Yesterday the scope seemed to return to zero fine but the previous session it appears to have returned low unless I goofed up something when resetting the zero (it was hot/sunny/I was tired). Nothing seems loose on the mount and the group sizes don't indicate the scope is moving around on shots. I am strongly wondering about a scope issue but don’t know if I’m missing the forest through the trees with my results.
The only thing I can think to do is load up some rounds and get a tall paper at 100, shoot a group and then dial up near the maximum I can, shoot a group, return to zero shoot a group. Figure that would check return to zero and also a better indicator of how accurate the MOA dialing is. If this is screwy then I have a scope issue.
Bit frazzled with everything going on this time of year already. You're not going to hurt my feelings pointing out an obvious issue, I just want to get shit working as expected, haha.
Range conditions depending on the day: ~24.5-25 inHg, 60-90F, low humidity.
208ELDM: published G7 0.337, velocity ~2750fps
181hammer: published G7 0.272, velocity 1: ~2900fps & velocity 2: ~2950fps (two different loads I was checking)
Last week I zero’d the 181hammer at 200 within an inch (so factor in that slight potential for error), the 208eldm was an inch or so lower but close enough of a zero I’d land on paper while checking drops. I put a target out at 1043yd for the eldm and dialed in 26MOA, landed them basically right on in terms of elevation. Brought the target in closer to catch a small charge ladder of the 181hammers (in the 2900-2950fps range) at 550yd and with 8MOA left impacts ~9” low, this seemed odd indicating a large velocity or BC variation, IF the rifle was still zero’d but I was out of test rounds.
Yesterday I start at 200 and shoot a round of the 181hammer and 208eld, they’re all low needed to come up 2MOA to zero the hammer and slightly low 208eldm. Then moved the target out to 426yd: 208eldm 11” low with 5.5MOA dialed, the 181 hammer groups were 6-7” low with 5MOA. This seems odd after just zeroing at 200yd to be that low with the given dial ups. Moved the target back to 666yd, first hammer rounds were in the dirt in front, I added 3 more MOA on the dial and caught the last 2 of each: ~2900fps group was 12.5” low with 15MOA, ~2950fps group was 9” low with 15MOA. The 208eldm was 15” low with 15MOA. None of this was looking right, I was out of hammers but had some eldm left, I moved the target back in to 200 (actually ended up at 190yd), return to zero had the elm 1.5-2” low (IE basically returned to its zero from the morning). I put a couple rounds on paper with 3MOA wondering if the clicks were notably off (should have flipped the target and did a greater dial up amount for the test) and things moved ~6”.
Generally I’m baffled. The data yesterday suggested its tracking at .79MOA/100yd BUT if that was the case there is no way I’d have landed those shots at 1043 on paper with 26MOA dialed (similarly this indicates my chrono isn’t massively out of calibration). Yesterday the scope seemed to return to zero fine but the previous session it appears to have returned low unless I goofed up something when resetting the zero (it was hot/sunny/I was tired). Nothing seems loose on the mount and the group sizes don't indicate the scope is moving around on shots. I am strongly wondering about a scope issue but don’t know if I’m missing the forest through the trees with my results.
The only thing I can think to do is load up some rounds and get a tall paper at 100, shoot a group and then dial up near the maximum I can, shoot a group, return to zero shoot a group. Figure that would check return to zero and also a better indicator of how accurate the MOA dialing is. If this is screwy then I have a scope issue.
Bit frazzled with everything going on this time of year already. You're not going to hurt my feelings pointing out an obvious issue, I just want to get shit working as expected, haha.
Last edited:
(Seriously, it’s one of the things I do for a living) and if you have another scope that you trust then don’t mess around with the one you have lost confidence in... especially you want to get the system up and running quick... You already have a firm grasp on what needs to be done and how to do it
