Magazine fitment - FAB Defense GL CORE MAG CP - M4 Survival Buttstock w/ Built-in Mag Carrier

So, one should know that if you purchase this buttstock, you will either modify all the metallic mags you intend to use with it, or e limited to polymer mags. Promags do capture into the catch, but no metallic mags do. For 223/556, this is not necessarily an issue, as polymer mags are plentiful. However, the build that I was making, and purchased this for, is chambered in 6.5 grendel, which is limited to metal, or Amend2 (faulty) mags. Just something to bare in mind, while considering this product. The build quality IS good, and honestly needs no instructions. The mil-spec clips come installed. Don't like them/can't use them? Use a punch, in the clip release holes, and Bob's your uncle. For those people considering the overall weight; this unit is almost solid polymer. The included mag is for 10 rounds of ammo. If you use a 25-30 rd (or dare I say 60 rd, or drum), it gets - wait for it....- EVEN HEAVIER. Know what you're buying, and anticipate the changes.

Bottom Line: If you plan on chambering in 223/556, and don't mind using polymer mags, buy this. You'll love it.