Sitting here bored thinking about stupid situations. In the midst, thought of one of those hypothetical "Hi, Andrea!" questions.
The .375 SOCOM was designed to use an AR-15 lower with a dedicated .375 upper. So, let's say you have one of those uppers. Now, the magazines for it by design fit into the standard STANAG well on an AR-15. As things would have it, a 10-round .375 SOCOM magazine is identical to a 30-round 5.56 magazine.
So, if you have the upper, can you buy all the standard capacity magazines you want, because all you're buying is 10-rounders for your gun?
The .375 SOCOM was designed to use an AR-15 lower with a dedicated .375 upper. So, let's say you have one of those uppers. Now, the magazines for it by design fit into the standard STANAG well on an AR-15. As things would have it, a 10-round .375 SOCOM magazine is identical to a 30-round 5.56 magazine.
So, if you have the upper, can you buy all the standard capacity magazines you want, because all you're buying is 10-rounders for your gun?