i have a bushmaster predator with the smooth free float handguard and want to add a rail in front of my scope for night vision. i have access to machinery to drill and tap my handguard. i want to know if the diameter is the same as the handguards that are already tapped for "add on rails". has anyone actually done this, i saw suggestions on ar15.com for some rails, but no actual experience doing so. i could probably do some customized shaping with jb weld or something, but if i didnt have to that would be great. i also know about the handguards available but i want to keep the one i have if possible.
