I have a Savage model 12 F class in 6.5 284. I have bedded it with Devcon 10110. The rear tang is floated and the barrel is floated .It strings a group of 4 or 5 vertical but stops going vertical after 4 or 5 shots and starts shooting back in the group. It will shoot .7 or .8 at 200 yards and not to prone to stringing. My load is Lapua brass cci br2 primer 51 gr of Hybrid 100 powder and Sierra 142 match kings jumping .0015. I have been hunting and shooting since 1963 and reloading since 1966. But this is my first attempt at target and long range shooting. Any ideas on how to correct this problem would be appreciated.