Tim LeGendre, the developer of the .450 Professional and the .450BM makes a conversion for the 450BM called the 450Corvette. As a fellow firearms engineer, Tim did the conversion for me, but swore me to secrecy on how it actually works. Long story short, it runs the .450BM factory ammo as well as handloads past the "wall". The wall is about 44Kpsi, at which point you have extraction, and the appearance of pressure issues with the stock configurations. Some guys run M16 carriers with heavy buffers and get a little better case life with a little better performance. Basically, at the 44kpsi, the pressure in the case does not drop fast enough and you are trying to unlock the action with the pressures still too high. Being able to run up closer to 55Kpsi without tearing up brass lets us push either heavier bullets, or lighter bullets faster, than the factory fodder. Tim uses a proprietary gas system that allows the higher pressure as well as the lower pressure rounds to be shot through the same rifle reliably.