AR 15 sighting issue

[tbmaker]

My friend brought his Colt AR over to look at. It shoots 6" to the right at 50 yards. That's the closest we can get it with the peep cranked all the way over.
Never worked on a AR, worked on most other types of firearms.
It does have a DPMS fore end that seems to have some nasty torque signs with oblong holes on the ends, like someone used a spanner wrench to try and twist it.
Does the front sight come off drifting the pins out?
Is the fore end threaded on some way?
Any suggestions would be appreciated.
 

[Reverend Recoil]

The front sight is removed by punching out the sight base/barrel pins and the gas tube pin.  It sounds to me like the front sight base is not straight.  It may be replaced with a match sight base that has set screws for windage adjustment.  Complete instructions may be found on the AR15 Build It Yourself forum.
 
http://www.ar15.com/

[tbmaker]

Thanks for the link.
Front sight has some play on the barrel but the pins refuse to move.
Took it out and shot it yesterday, with the front sight base pushed tight to the right it shot just fine after moving the sights back to center both ways. Nice little shooter. Now I'll get the friend out and see what kind of shooter he is.