Made this to carry a spare magazine with AR platform at all times for Unfortunate Americans living in the following peoples republics: California, Colorado, Connecticut, Hawaii, Maryland, Massachusetts, New Jersey and New York.. This stock will be helpful to carry an extra magazine. NOTE:Your printer must be able to print to a height of 180 mm, that is what this is, also I made the walls thicker than a standard butt-stock....so it can handle some abuse! it will accept any size mag. Added a optional Butt-plate with gripping grooves. Added split version of mag release buttstock...rotated to lay flat,I included the G-code that I used to print this thing. be prepared to wait a long time, it takes about ten hours! But it is well worth it.....especially if you live in one of the aforementioned republics. I used a colored PLA, because it seems harder. I will paint with Black spray paint later. I added a spring loaded lever to adjust the stock. Had to attach some sandpaper to a broomstick to slightly ream out the slide area to make it move freely. UPDATE: uploaded a stock with built-in mag release button...also made it 1 mm bigger so it should slide a little easier on tube. UPDATE: Just added Molon Labe emblem to design!... borrowed from http://www.thingiverse.com/thing:507232 UPDATE: uploaded sliced in half version of stock 11/11/14