If you can check each shot POI, it will be more significant in diagnosing the problem. Do they jump back and forth high and low,or is it random. Back and forth I would think indicates something is loose.
Another thing is the rifle might not shoot the180's well. Try a few std 240 gr.
My 44 Marlin will do better than 4" at 100yards shooting Speer Semi Jacketed Flat points. I use to do that with the iron factory sights before when my eyes were better and now I have a cheap $50 NcStar scope on it and it will do the same as it did before, maybe a little better.
One thing I did find out when fiddling with scopes is that the typical mount that fits a Marlin 94 will not hold a standard length scope that you might put on a full size rifle. I had an old Weaver V7 and then a a Leupold and they both hung out there too far unsupported . I could litterly move the objective lens end around. Problems went away when I put a shorter scope on it
Last edited by saddlesore; 08/04/14.
