300 Blk is ideal for suppression as it has subsonic ammo that will feed and cycle reliably. With subsonic ammo, a suppressed 300 Blk is Hollywood quiet. It is just one of many advantages of the cartridge.
Oddly enough, I just took a break from converting 223 brass to 300 Blk before reading this.
There are a lot of benefits to having a suppressor. If you buy one for a 30 cal. with a Q.D. you can use it on other smaller calibers from 30cal. to 223 Just buy the Q.D. attachment for the other rifles. Then you only have one suppressor.