KWG- The pros for the 6x45 and 25-45 is that they two of the easiest wildcat cartridges to form cases for. The cons are you can't use very long bullets and still fit in an AR magazine. Great in bolt rifles, though where the magazine is longer than 2.260". Longer bullets will end up with the ojive seatted deeper than the case mouth. I think the heaviest flat based SP Spitzer which fit in the 25-45 is the 87gr Speer. In the 6x45 it may be a 80 or 85gr SP Spitzer. If you want better long range performance with a higher BC bullet, you need to use a shorter case, like a 222 (or a 221 if you want to use a .30 cal 220gr projectile, ie 300BO). Using heavier weight bullets between 6mm and 7mm is preferred, between 90gr to 135gr. But the 223 case will be too long and must be shortened. Look up the 300Ham'r on the Wilson Combat website and you'll see a very neat cartridge designed from the 223 specifically for the AR shooting lighter. 30 cal bullets for short to medium range boar hunting. To shoot a higher BC bullet in the .264, 277, or .284 sizes you need to shorten the 300Ham'r case somewhat to approximately 222Rem size. That's what the 7mm Raptor is. A little more shorter case and you have the 277 Wolverine, another very efficient cartridge which has some industry support. -Mark & Belle
