pick up my first colt ar 9mm last week and the flash hider had looked like it had been put on with a set of vise grips, a big eye sore. the question is, I bought me a new colt birdcage threaded flash hider and i am having a hard time trying to remove the old one, and am afraid that if i put to much pressure on removing the flash hider that i will damage the upper reciever or throw the front site out of line. i am new to ar-15's and dont know to much about them. will the barrel itself twist if i apply alot of pressure to the flash hider.  

tackleberry,

You do know that the 9mms use a different thread than the .233s right?

If you apply too much tension to the barrel you will bend it. Clamp the barrel as close to the muzzle as possible. Differential temperatures can help too. Are you sure the flash hasn't been permanently attached?

I finally got it off and had to clean the threads up from the old locktite and put the knew one on. so far so good, i will take it to the range today and see what kind of damage was done.  thanks.