Fixed and floating barrel nuts come in sizes 0.190 to 1.5 in. and are traditionally manufactured from alloy steel Fixed and floating barrel nuts come in sizes 0.190 to 1.5 in. and are ...

You can see from the pictures the barrel nut lines up with a cutout in the ... This rail is a very affordable way to get into a free floating rail for your AR15/ M16/ M4 variant.