Thread: Down loading 243 win to 6x45 velocities

Originally Posted by rusl

This is really interesting, I was thinking about a 6x45 but after a bit of thought I was pondering downloading a 243 might be simpler than custom building something the kids will probably grow out of pretty quickly.
Is it normal to get good accuracy when downloading or have you just struck it lucky, I thought I had read that by downloading pressure and velocity were kind of random and accuracy opened up, but that also may have been when using case fillers etc.

Every cartridge I've tested the IMR 4198 Reduced loads in I've been able to find superb accuracy, the 243 example above was one of the worst! (and most people would be pretty happy with a 3 shot group in the .3's right) You should see the group my bitsa M7 6.5CM shoots with 123 eldms and 30 gr of the 4198. My 223 also shoots tiny little groups with 14gr of it behind a 55gr SGK.

Whereas the powder that most people use and is normally recommended to use as low as 60% of the max charge (ADI AR2206H) often throws some pretty average groups, ive tested it in the same rifles, and the precision just isnt there. If you are going to do it, do yourself a favor and use IMR 4198. In any case from 243, 260, 6.5CM 7mm08, or 308 30gr seems to be the sweet spot, with a 120-130gr projectile.