wanting to instal a Tango Down pistol grip. when looking at my Bushie lower, i noticed that the screw holding it in place is not a slotted screw, like on the M16s I'm used to. it seems to be a female hex. is there a hex (allen) wrench that big? is it metric or british? i wouldnt mind buying another set of hex keys anyway, the set i have right now dosen't have a wrench that big...so if i have to buy a whole new set, just to take off this pistol grip i wont really care. i just dont really feel like taking my lower into the hardware store to test wrenches out. that might be a bit dodgy. any and all help will be vastly appreciated.
respect.