ar front sight problem

[shootme]

Just bought an Bushmaster AR competition model. Went to "zero" per the book which requires adjusting the front sight. Suppose to depress the detent and turn the front sight up or down. Well the sight will not budge even using a pair of pliers...in either direction. center of group is about 2 inches low at 25 meters.

any ideas as to how to break this loose without damaging the sight post?

Thanks

 

[madcratebuilder]

Do you have a front sight "tool" or are you using the nose of a bullet?

 

[Quentin2]

Are you pressing the detent down enough? Using two finishing nails you can do this or a front sight tool, don't use pliers. If it doesn't move try soaking in oil or penetrating oil first.

 

[wingman]

Kroil oil will do the trick.

 

[shootme]

Yes I tried a bullet and an small hex wrench to push it down as far as humanly possible. I've tried several different oils, break free, BP blaster, transmission fluid. .....nothing yet....don't have one of those tools, guess I may have to get one.

 

[Marquezj16]

Sounds like you need to replace the front sight post. It should never be that difficult to adjust.

 

[DnPRK]

Some competition ARs lock the front sight post in place using a tiny allen set screw inserted from the bottom of the front sight post opening.

http://www.gswagner.com/arsight/arsightmods.html