What exactly do I have to get to mount the FF site on a Mossberg 500? I really would rather not use the picatinny base and read the best is use a 336 base, which keeps the site lower to the barrel.I assume this Is this a FF adapter base made for the 336 not a Weaver type base used to mount a regular scope? ONLY thing that Is that the picture of that 336 adapter looks like it only has 3 holes in it,assuming 2 would be for the site to base and that leaves only one to mount the base to the gun. The picture may not have been the actual adapter base for the 336. It is pretty clear if u use the picatinny rail but im confused if you go with the 336 method. Any help would be greatly appreciated.