I just bought a Bushmaster xmem15 rifle preban for 800.00 dollars yesterday. I took off the A2 flashider last night. I was going to put a 5.5 inch flashider in with holes when I realized I scratched the threads. Now I need to buy a die? What size is it? Looks like 9/16x28 /Right hand thread? Help!!!!

1/2-28 for muzzle threads. Depending on how bad the scratch is you can probably chase the threads with the original A2 flash. Go slow, use lots of oil.

Why would you want to put a 5.5" flash increaser on it?

Thanks for the info. I hear the 5.5 flashhider hides the flash better at night. Is this true or is the orginal A2 flashider the best one?

You do know that a flash hider doesn't hide the flash, right? If designed and installed correctly, it leaves you an open area in the fireball (which looks about 3' in dia) to see through...And may or may not reduce muzzle lift, depending on location of slots/holes...

That said, as soon as you fire at night, your night vision goes all to hell...

Wouldn't the Vortex be better, and much shorter?

Just chase the threads, it should be all right.

Thanks for the help guys. I order a 1/2x28 die from Brownells for 20.00.

No, esp on 11" barrels, even 20" post ban barrels have little muzzle flash with proper loads. Flash [b]hiders[/b] are designed to keep the flash from blinding the shooter. Ref the hider used on the M2 HMG. Flash [b]suppressors[/b] actually break up the flash so that it cannot be seen by anyone. That said the 5.5" flash does neither of these, the flash from them with 11" barrels is intense, as they act as an expansion chamber for the gas. As previously stated, the 20" gives off very little flash to begin with. The 5.5" flash was not designed to do anything except make an 11" barrel look like an XM barrel.

I've stood in front off (100 yards downrange, 1" from the bull) a 20" barrel equipped with a Vortex and all I could see was an occasional spark much like a chimney would give off at night. This in full dark with very little starlight.

Simple test really, go out shooting at night and take a friend. We do it prolly once every two months around here when we wind up staying too late.