Board Thread:General Discussion/@comment-4957813-20140510034158/@comment-24260323-20140529170820

If you can swap out the entire magazine, then it probably isn't internal, it's more of a detachable mag. The internal magazine I'm thinking of is kind of like a Pump action shotgun's tubular mag, or a bolt-action rifle circum. WW1-WW2 with a fixed mag (i.e. guns that required reloading by hand or by clips).