I've had a ruger 30-06 with wood stock for years and it has always shot good (1 inch groups at 100 yards) with 165 grain Remington Core-Lok's. I keep it in a safe and I don't THINK the stock has been wet at any time. I have not shot it very much lately. I mounted a new scope on it (Swarovski 2.5-10x50 Professional Hunter) in Leupold mounts and went to sight it in today. Scope mounts are tight and the scope is not touching the barrel. The ammo was new and from Wallyworld. I did use ammo that I had for the first 5 shots. I had a good rest and ended up shooting a 4 inch 5 shot group, or a 6 inch 6 shot group - take your pick.
This is very uncharacteristic of this rifle and though I probably don't shoot as good as I used to, I felt good about my shooting. The first shot at 25 yards was 5 inches right and 1 inch low. Moved correct number of clicks, next shot was dead on at 25. Moved out to 100 yards shots centered at 4 inches high and 1 inch left (3 shot 3 inch group). Moved with clicks again. My last group centered bullseye, but was awfully big. I can't imagine that the problem is with the scope or mounts.
Any idea what I might could do? I decided to keep this gun years ago because it shot good with cheap ammo... Are Core-Lok's getting cheaper/less quality control? If you think so, I'll go back to Federal Premium. True at 100 yards I can kill most anything with a 4 inch group, BUT at 300 yards - I'd miss nearly everything with a 12 inch group and at 400 it'd be absolutely useless to try.
Any tips would be greatly appreciated.
Thank you,
NitroSteel