I have been working on loads for my 257 stw, rifle likes the 100 bt and the 130 wildcat bcfb bullets. The thing is that from the heat I am having a heck of a time to get a good group from my heart beat showing up in the scope. Rifle is putting the bullet right where the crosshairs are located on the paper, just shooting in a t shirt for groups in this heat sucks. Temp is 98 or better, I may just have to wait till it cools down to work on the groups. I am getting .75 groups at 100 yards. Just that is the amount of movement that I am getting from my heartbeat. I have been shooting from a bipod and from a sight vise. I know I can get a better group when it cools down with a hunting jacket and all just wondering if there is something that I can do know that would limit my heart beat from showing up in the scope. Might just have to sand bag the rifle down just don't like to shoot from sand bags and hunt with a bipod. would sand bagging the rear of the rifle and having the bipod rest on the bipod limit the movement. I might have answered my own question. Thanks oldfamily.