Is there different sight tools for the front sight?
My sight is square and appears to have 4 prongs.
Thanks.

There are front sight adjustment tools for the A-2 and the old A-1 front sight posts(A-1s are round posts with 5 catches, A-2s are square posts with 4 catches).

The sight adjustment tools are not expensive, but you don't need a dedicated tool to adjust either type of front sight.
The tip of the 5.56 round is what I bet most of us use to adjust elev. for our front sights. The manuals always said use a cartridge tip.

The cartridge tip will be a little deformed after you use it for sight adjustment, but you should be able to use the round for plinking without any problems, just not in a match. Also, make sure you use a fmj ball type round, no soft point stuff.

HTH, Mike H.

My front sight would not adjust. Even with an adjustment tool, I could not turn it by hand. After clamping the tool in a pair of locking pliers and turning, the four nibs broke off the tool. Now they are wedged in the openings and I can't budge it, not even with locking pliers on the sight post.  Pisses me off...a brand new rifle and no way to sight it in.

redx,
Try turning the rifle upside down and filling up the hole under the front sight post with penetrating oil, let it soak overnight.  May be able to twist it out after that......