dont bother. if you want more velocity go to a .22-250 or down to a .204, the .204 will easily top 4 grand with 40 gr bullets, and the 40 grain .204 bullets have higher B.C.'s. you are doing something with this cartrige that it wasnt intended to do, this means more wear and tear, and a potentially unsafe situation. at a very MINIMUM have your chamber Akley Improved.
