Got a left hand mag from Orion for 30 cal he mirrored it 100 percent and I did the mods to flip the bracket so the mag is on the opposite side and installed a Ambi cheek rest making the m3 left hand friendly by flipping the bottom piece you are able to do some file work on the magazine cross bar to get the mag to latch aired it up tonight and confirmed the mag cycles with out a problem this mod could be done with a steady hand a Dremel a file and 2 longer m3-.50 X10 screws Orion can make left hand mags as per request I ordered the Ambi cheek rest off eBay but he could probably print one too a flat washer about .070 thousandths needs to go under the blanking plug and I enlarged the hole in the bracket to 5/8 for clearance of the plug if you have a gauge the you would need to follow the reliefs cut into the bracket for the gauge removing the metal for gauge to fit or get a blanking plug