[smitlar]

My son just got an AR-15 with flat top receiver and 16" barrel with standard gas block integral front sight. The problem is an add-on carry handle with an A2 style rear sight. The rifle is shooting about a foot high at 75yds with the rear sight bottomed out. The front sight would have to be raised above the ears to achieve alignment.

Can someone tell me what type of rear sight would be compatible with the standard AR front sight? My son likes the look of the carry handle, but needs to have usable sights.

Thanks, Larry Smith

[txhoghunter]

Larry,

Most aftermarket AR-15 carry handles/BUIS will be about the same as far as sighting goes and amount of adjustments they can make.

This might be more of a problem with the gun as opposed to the sights. My only recommendation would be to take it to a gunsmith to see if there is something that he sees is wrong or fixable.

[smitlar]

I have pretty much come to that conclusion, that something may be out of wack with the rifle. Last time we shot it, we had an EOTech sight on the rail, which confirmed where the iron sights were pointing. We'll probably take it to my gunsmith next time my son brings the rifle here to shoot it.

[briansmithwins]

Look at the front sight base. You're looking for a 'F' mark.

Which I bet isn't there. Flat top upper ARs require a higher F FSB to get zero. It's a detail that's often missed.

If it were me I'd be taking the rifle back because it can't be zeroed. Changing out the FSB on a rifle ain't trivial and shouldn't be your problem.

BSW

[MrCleanOK]

BSW is probably right. I'd put my money on a standard front sight base. You need and "F" marked front sight base (there is an "F" stamped into it).

It is possible to get a taller front sight post, but it will stick above the ears of the FSB. The real fix is to return the rifle or parts, and get an upper with an "F" marked FSB. Once a FSB has been drilled and pinned to a barrel, those two parts are mated for life. You can't just replace the FSB.

[smitlar]

There is no "F" stamped on the FSB. Thanks very much. You guys called it.

We learn something every day. Excellent help!!