What are you going to do the the BR case to improve it?
? When you go to a larger case your velosity increase is 1/2 of the volume increase of the case. With the BR case there is ver little room to increase it hence you will get about no gain in velosity. You can also improve the accuracy potenical of some rounds by improveing them, but the BR case in it`s present form is probibly the most common case in used today by the bench rest crowd. I know that I`m a good one to talk with all the different wildcat I have laying around here, because I know that when it comes to building a wild cat rifle it`s not a matter of need, but a matter of of haveing something different that will do the job alittle better. ( And, Most of that is in our head.)
