Try 90 GR. of RS and some CVA slick load patches or make your own with bore butter. Just get them greasy and saturated not too much though. I would start with a clean rifle and mark your range rod with a piece of tape or marking pen when seated properly. I'll bet with a dirty bore it may seem that the ball is on the powder when in fact there is a little space there. That will destroy a patch and accuracy without a doubt.