I recently purchased a new Zeiss Consquest 6.5x20 for a Sako 75 7mm Rem Mag I just purchased. I have taken it out 3 times doing load development. I tried 4 different powders and found RL19 shot 8 consecutive 3 shot groups between .3 and .6. I went back out yesterday with the same loads, using the exact same components. My fouling shots shot under an inch and my first group went to .7. What is intersting is that all my groups seemed to have the same pattern, where the first and third where in the same hole and the second was a little right. So on my second group yesterday my third shot goes about 1.5" high, and at 20x mag I didn't notice any flinch but thought it might be me so I put a fourth into that group, now it wen 2" right. Well I shot two more groups and they were 2"-3.5" with no distinct pattern.
I checked the mounts and rings but everything seemed tight. I assume if the scope slipped in the rings that my point of impact would change but that it wouldn't necessarily spray randomly. I didn't notice anything loose on the scope, nothing seems to be moving around.
The only thing I could deduce is that I did just purchase some new boxes of bullets, I shoot 160 gr Accubonds, and that maybe they are bad. I had noted that my first 6 reloads of the day were of the old lot, and they went into the fouling shots(4) and the first group. I don't think it was that.
I've never encountered a problem like this as I'm new to this level of load development and accuracy. Can some of you with more experience give me an idea of what you think may be the problem and some advice on how to isolate what the problem is.
I thought I might try to put another scope on this gun. All I have available is a Bushnell Elite 3200 3x9, but that should probably work.
I really really like this scope. I had checked the tracking and it seemed spot on.
P.S. I wouldn't think I would have a problem with this quality of a scope but I remembered reading this post while researching: thoughts on zeiss conquest scopes