The G.M.F.G. (Glock Magazine Foreward Grip ) is a foregrip designed to hold one extra magazine on a firearm, while also acting as a vertical foregrip. The magazine is held in place by two spring tabs, and requires no fumbling of buttons. In a stressful situation, simply pull, and the magazine is already in your hand, pointing forward. Afterwards, there is still enough foregrip to provide enough purchase for two fingers, and a nice thumb shelf to make it an effective stubby grip.
This magwell is designed using the dimensions of the 9mm/40calibre glock models, that are identical in exterior dimensions. This will most likely not fit 10mm/45acp size magazines.
The tolerances of the magwell should allow aftermarket magazines to function, but so far I have only tested original glock magazines, and the Korean extended magazines.
Now it's time for the legal part. I am not in any way affiliated with Glock, and the Glock trademark and all official glock merchandise are the respective properties of Glock.
This grip is not intended to fit on a Glock handgun. This grip is intended for Pistol Calibre Carbines, (PCC) that utilize Glock magazines, such as the MechTech rifle conversion kit, Keltec Sub2000, and pistol calibre Ar15's.
Attaching a foregrip to a handgun in the United States, (which reclassifies it as an AOW) without the proper paperwork is a felony. This is only intended for Rifles, Registered SBRs such as the CAA Roni kit, or Non-NFA firearms, IE Ar15 9mm with no stock and overall 26 inches in length.