FSB Replacement

AR/M4 AR Technical Discussion
1

I’ve got a barrel with no FSB – it had a Larue GB on it when I got it but I want to go back with a standard FSB. It is drilled for pins – looks like straight pins – but it seems like would be tricky to get a new FSB and drill it to match. Is this doable or is it a lost cause? Does anybody have a recommendation for who might do this? This is going to be my first from-scratch build – kind of a low-budget beater/learner project focused to make use of this barrel – so I don’t really want to spring for a new barrel assembly.

I suppose I could always go to a set-screw type railed gas block with a fixed sight on top but am not crazy about the idea. Partly because I don’t like the set screws and partly because they just don’t look right.

2

It’s almost a lost cause to mount a new FSB with those old holes in the way.

There are a couple clamp-on options though.
Armalite makes a Clamp-on A2 type FSB.
PRI and YHM have clamp-on flip-up front sights.

I quit doing FSB swaps and am now referring the work to Adco.

3

As Randall said the YHM is a good option. It clamps over the bbl and uses 4 set screws. It’s pretty nice. I’ve installed a few of these, they have a bayonet lug and a flip up front sight. I degrease everything and use Rocksett on the screws and then stake them to the FSB.

4

Thanks guys, that’s kind of what I figured…

I will probably sell it off and go a different route. I was gonna do kind of a retroish A1 KISS type build with it and while it’ll work fine with the railed or flipup gas blocks, it won’t be what I wanted…

5

Well, you could always place it up for sale or trade.

Not sure what it is that you have, but I have a M4 contoured 14.5 colt barrel I am thinking of getting rid of. I might possibly consider a trade!