I'm about to start reloading for my buddy's AR in .450BM-a cartridge I know little about. From what I read it seems I need to keep pressures near maximum to ensure the case seals in the chamber. Any tips, advice, or pet loads would be appreciated.

I am interested too because I am going to buy rifle chambered in this caliber. Hope to be a good companion to .460 Rowland pistol.

I bought a 450 BM along with a lot of brass and I regret the heck out of it. This caliber should never have been produced with a small rifle primer, it should have had a large primer. I have had hangfires, misfires, unburned powder and erratic loads. I had resolved to buy every powder and every bullet listed in the Hornady manual to see if ANY of them actually worked but poor powder availability and shoulder surgery interfered and now I have completely lost interest. My advice, if you don't have one, don't get one. If you really want a big bore get a 458 SOCOM, I have had zero problems with this cartridge. If you do have one and really want to try to make it work, use magnum primers, maybe use fillers to take up the excess space in the case. Take a look on the 450bushmaster dot com fan page, special crimps, magic powders and the like. If a cartridge needs special crimps and magic powders there is something wrong with it. And there is something wrong with the BM, the primer is too small. BTW, I had the same problems with the 454 Cassull, a similar cartridge with the same problem, too small a primer and the same results.

Odd, the .454 has been used for many decades by thousands of shooters without problems, myself included. I can believe design issues with the BM, but not the Casull.


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