Re: goodgroupers 6br imp
Sorry I missed this post for awhile. I skipped right over it several times and never saw it! [img]/ubbthreads/images/graemlins/confused.gif[/img]
I have a standard "high side turn" 6mm br and the improved version with a 40 degree shoulder. Both work great.
I have a friend who just built a regular 6br fast twist and he noticed low standard deviations as normal with the short case, however, I had many more single digit deviations in my improved than he did with his standard. Now, that might just be a coincidence, but I had something like 23 or 24 of 26 loads that had sd's in the single digits and the few that were out were an sd of 10 or 11! This was supposed to be the design intent of the sharper shoulder-to burn slightly slower powders more efficiently with heavy bullets and with these two guns, I can see some evidence of it. However, it might be picking the fly crap out of the pepper because the standard 6br is not too hard to get uniform velos out of.
You will have the added cost of dies, reamers, and fireforming if you choose the improved version so that's a consideration.
BTW, my improved shoots 30.5 grains of Varget and pushes a 95 grain bullet at 3050 from a 25" barrel. My buddies gun shoots the same bullet at 2950 with 29.5 grains of Varget from a 28" barrel. Both of our rifles will get an extra 100 fps over our favorite loads but they do not shoot quite as well going that much faster. Something to think about.
Also, I tried all the small rifle primers with my optimum charge of varget and the Federal 205gm's gave the best accuracy. The CCI primers were touted to give more velo but they shot almost the same speed as the Fed's. I had a hard time getting the oversized CCI primers into the extra tight Lapua Br brass primer pockets too so I just went back to the Fed's.
Ps. If you do go with the improved version, I have all the info you need to have to get the right gear and it will be less painful for you than it was for me! [img]/ubbthreads/images/graemlins/wink.gif[/img]
If it's not far, it's boring.