Polymer80 GCA Compliant' 76% Blank

[My Toy]

MMC Armory is advertising the above referenced pistol lowers. I know this is a moot issue for us in MD but is this an effort to work around the recent ATF Rule. Ad says it requires more "machining" and the rails and pins will be shipped separately. The additional machine is explained that it can be seen by looking at at the picture but it is kind of hard to see. Anyone know more about these lowers?

Polymer80 PF940CV1 ATF Compliant Compact Blank - Black

mmcarmory.com

 

[My Toy]

Actually looking at one of the views it looks like there is some material to remove where the rear rail module fits in the back of the frame.