Well, I know the Sav. 340 can be accurate....I had one in .22 Hornet long time ago....and it was very accurate. I do remember having to re-tap the side mounting scope mount holes because they stripped. First I would confirm that it is a rifle problem. You should use some type of ribbons placed along the range and only shoot when they show the same condition. Also, make sure all parallax is adjusted out of your scope. Make sure your shooting platform is solid and since that models trigger pull is quite hard, shooting decent groups takes a lot of concentration. 22 calibers seem to favor a good jump...at least .060"...I would stick to 50 gr. bullets playing with seat depth. Due to the rifles design (with no rear action mtg. screw), your idea to bed between the 2 mtg. screws has merit. Also experiment with tightening torque on these screws....and check how solid the scope mount is fastened to the receiver...it's cantilever design can attenuate problems.