Will front sights inner change?

[ibuymilitaria]

Gentlemen, I am no AR15 Guru. But I would like to know if the front sight assembly with a bayonet lug on a rifle with a standard weight barrel will fit an A2 H Bar with out the bayonet lug. Can they be swapped out or is there a diameter difference? or anything that would not permit me from making this swap. Any takers! Thanks Jeff B

[browningautorifle]

The front of the light barrel(12 in twist) is .625 at the sight. The match barrel is .750. The heavy front military (7 in twist) is .730 at the sight base. They don't swap very easily between rifles anyway. The sight is swaged on and then the pin holes are drilled after. I haven't had too good luck changing between barrels. Remember, they're taper pins.

[ibuymilitaria]

Thanks for the up date. Was looking at a blue label H bar upper but as you know there is no Bayo lug. I have had a Colt lower for a number of years just never went for it. Jeff B

[jmoore]

Its a royal big pain to install a new UNDRILLED FSB to match existing taper pin holes, but I've done it for myself. Nobody would pay for the labor(time) required to do it right, though! Swapping used FSBs is an exercise in futility if you expect to use the taper pins to retain them- they just don't match!

There are other ways of doing it, but it won't LOOK like original factory work.

[browningautorifle]

One time on a jobber, just to retain sanity we mig welded a spot on the bottom of the back ring to get things top dead center. Shot just fine!