Originally Posted by Camshaft
With that kind of performance, i could probably bring myself to pull the trigger on a 6mm build. Hope to see some real world #'s soon, and maybe have a reamer available by fall. I am assuming Retumbo would be the go to powder in this cartridge?
here's where I'm at right now:
* I've owned five or six 6mm Remingtons in the past; with two being the Ackley versions. I kinda know how to make a 6mm work by now. Still I think the Ackley would be at it's best with a 130 grain bullet (if there was one). I've also shot with buddies that did the generic .243 as well as the .243AI and kinda know what's not so right with them by know. (short barrel life, as well as a short case life)
* now I shoot the 6/250AI, and it has it's pluses, and some minuses. The neck is still too short leading to a shorter than normal barrel life, but still longer than the .243 (maybe 25% at the most). I do think the 6/250AI is a tighter grouping round than a .243 or the Ackley version, but that's debatable.
* now I've been working on drawings for a new wildcat that uses .243 cases (they're common and cheap). I want the 6mm remington neck length, but with either a 30 or 40 degree shoulder angle to help put the T.P. in the first half of the neck. The case I was looking at would use either a 1.44 or a 1.46 shoulder deminsion with a .455 O.D., and a .31 or a .33 neck length. I've also done a similar case off the .284 case that used a 1.38 shoulder, but have reservations due to case availability. If I go with the longer version, I'll have to use standard 6mm brass due to case shrinkage alone (this is a common problem with all 40 degree cases), but I probably have 750 virgin cases!
* now we move into the 6BG. It's one of those short fat cases that will group very well. The shoulder is 1.352 (I got that number wrong in my first post) with a .454 O.D. The neck is .330" long if memory is correct, and uses a 30 degree shoulder. Cases are formed from .243 brass, and keep the 2.045" length. Will push a 107 grain bullet to 2990 fps with 42.8 grains of RL22. This cartridge is kinda like a 6BRX on steroids! Is super efficient. Cases should be easilly formed from standard .243 brass. I need a reamer!