Yellowlabman:

I missed somewhere you were shooting an A-bolt. Seriously, take the gun to your favorite gunsmith and have him cut that Boss off and recrown the barrel. It shouldn' t cost much more than the box of ammo you will need to find the " sweet spot" , for that particular load. Everytime you want to try another load, plan on doing it all over. In all that shooting, you are going to have to replace the nylon bushings a few times also...

I have a few a-bolts and bought another with the BOSS. I love the rifles, hate the improvement, and when I have a spare Saturday, off to the ' smith it is going.