I don't know how well that will do.
In Wyoming the 458 SOCOM sell very well, but I know of no one that has or wants a 450 Bushmaster. We have a lot of elk and big bears. So a super fast pistol bullet (2000 to 2200)is not as appealing as a 1400 to 1700 FPS rifle bullet. The bushmaster has a .451" bore so most of the bullets available are made for handguns. The SOCOM has a 458" bore so it's made to fire rifle bullets like those made for the 45-70, 450 Marlin and even some for the 458 Win Mag.

Maybe the demand will be good in other places, but I think they would do far better if they offered the SOCOM, even if they didn't do it in the American. It was made for the AR, so what would be wrong with selling them in the ARs?