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.

They sell long wrenche sets at my local Wal mart. Also Hex bits and srew driver handles to hold them. They are inch. The ones I have are 3/16".