The rifle itself is irrelevant. The magazine is the device in question and what type of firearm it was designed for. Again, centre fire, semi automatic rifle, then the magazine may hold only 5 rounds. There are legaslative exemptions in the Code and Act, but that's not what we are discussing here.
Look at it this way, if I design and manufacture a semi automatic rifle that can accept Accuracy Internation 308 mags, then I could use the AI 10 round mags as AI doesn't make any semi automatic rifle that can accept those particular magazines. That would be a reverse way of doing things, building a firearm to suit the magazine. Mostly it is the magazine that is built to suit the firearm. There are not too many companies that manufacture bolt action rifles, that also make larger capacity magazines for the bolt guns. It could be done, and then legal to use those "dangerous" 30 round mags in a semi automatic rifle, if you were to manufacture a semi auto that accepts those mags.