Originally Posted by -=ArchAngel=-
...Then how can the 121 do better? The one and only ballistic leg up the 121 is its muzzle velocity.(This is assuming that the 121 is fired at the same muzzle energy as you would a fs round, thus allowing a much higher muzzle velocity ) ...
Unfortunately, this is very unlikely to happen (in the U.S. anyways, not sure about Canada, while I believe Japan and the EU specify energy). A lot of folks hoped that .50 rounds would be able to be fired at a higher velocity but, they weren't / aren't. The way I understand it, here in the U.S. all of the safety recommendations (by ASTM) and insurance requirements are written around FPS and not Joules/ftLbs/etc.