Does anyone know whether a 24C is MA legal?  

Any thoughts from the hive?

Yes, but the FFL in MA has to be willing to use a "work around" to legally transfer it (frame ONLY). And then you ship the rest (no >10 rd mags unless mfd prior/on 9/13/1994). Many FFLs in MA won't do this, so receiver has to ask first.

Someone can move here with the gun and that is perfectly legal, as are FTF transfers between 2 MA residents with MA LTCs.

Interesting.  I guess that is why I see so many frames for sale in MA.  Never sunk in that it was  legal thing.

I just saw where a 24 is on the "list".  But a 24C is not.

The Feds define a firearm as the "action" (usually the lower/frame for most guns).

MGL defines a firearm as a device able to fire a shot. So if the upper is "missing" at the point of sale, it is not considered a "gun" under MA law. Therefore, guns that aren't approved can be obtained from outside MA via a frame/lower/action transfer thru a MA FFL and the outside-MA owner (or dealer) ships the upper separately (this is key to compliance) directly to the new owner.

Also, since the lower/action/frame isn't a "gun" under MGL, it doesn't have to be tested and approved by the state for it to be legally transferred.