Originally Posted by
TheSwaggernaught
The body cannot hold more than 10 rounds - from my understanding, these magazines are originally designed to be California compliant. The capacity is restricted by a "reducer" or spacer which is essentially an internal floor plate that rises up to 10 rounds. The spring is also only good to supply tension for 10 rounds. Even if you were to remove the reducer from the magazine, the spring will not be able to feed any thing because it has been shortened for 10 rounds only.
Bartons big country is selling these in massive quantities - they even say "pistol" on the side of the magazine. The CCFR has been handing them out as prizes.