Front sight/gas block removal?

[Cheeseybacon]

I've toying around with the idea of a holographic optic of some kind and realized that the front A2 sight on my Bushmaster is in the way. I'm assuming I'll need to replace the front sight with either a flattop gas block or one with a flip up iron sight.

My question is, how the hell does one go about removing the A2 front sight? It appears as though it's pinned in place, and I was just about to go grab my punches until I noticed that both ends of each pin appear to have a head of sorts on them, leading me to believe I can't drift them out. Is this true, or am I probably hallucinating?

My dad bought an air-powered demmel-like tool shortly after Christmas and has been eager to use it on something. I'm beginning to think he has the right idea.

How should I go about doing this?

[P-11 shooter]

Now, i'm no AR expert, and people on here can give you lots of different options. But I know you can cut the top of it off and file it down almost flush and out of the way. Not quite sure how clean it'll look but it's done all the time.

[Jay5oh]

They are drift pins. You can have a holo sight and keep the FSB. If your thinking aimpoint/aimpoint clone all you need is the QRP mount & spacer for perfect co-witness with the irons.

I'll post some pics of mine tonight...

[Cheeseybacon]

Originally Posted by Jay5oh

You can have a holo sight and keep the FSB.

I'm confused. Why would you want a holo sight AND the front sight block in use simultaneously?

[P-11 shooter]

No. the ones I shot had the red dot right on the front sight pin. Alot of people don't mind this, but personally it bugs the hell out of me. I just don't like the look of a red dot AND a front sight tower. Plus I hate having the front pin on my red dot. I know you can remove it but one of the AR guys are gonna have to tell you exaclty how.

My brother got the flip up front sight block on his AR and it is SWEET! that way if you want to use irons it's quick and easy. Maybe you can get one of those aftermarket.

[P-11 shooter]

Originally Posted by Cheeseybacon

I'm confused. Why would you want a holo sight AND the front sight block in use simultaneously?

Because their rifle has the tower and they don't have a choice. I think it sucks. But that's why i'm paying extra money for the flip up or 2 rail block.

[Lycanthrope]

Yes you can drift them out.

Yes, you will likely ruin them as you do it. FSB should be fine, though.

[Cheeseybacon]

Glad to know I can drift the pins out. I have no desire to go back to the A2 front sight, so I am OK with it being ruined in the process of being removed.

I'm studying my front sight some more and I'm beginning to suspect to that even after drifting out the pins, I still won't be able to get this FSB off without cutting it. First of all, there is a slight lip on my barrel, right in front of the FSB. It's not too tall, but it definitely looks significantly larger than the diameter of my barrel where the FSB is sitting. Will the diameter of the FSB expand a bit after I remove the pins? The thing looks totally solid and I can't imagine it moving much even after the pins are removed.

Also, assuming I could pull the FSB past this lip after removing the pins, I've now got to deal with the flash suppressor. I have a 16" carbine and I'm not certain, but I think the flash suppressor might be welded on to insure the minimum 16 inches of barrel length. I guess I need to measure it. As far as the law is concerned, where does the barrel begin on an AR15? Does it begin at the rifling or the chamber? Or does it begin as far back as the bolt lugs?


Lastly, if I my barrel is 16" on it's own without the flash suppressor and there is a good chance that I cant just unscrew the suppressor, can I do with with the barrel still attached to the upper receiver, or am I asking for trouble?

[fultonCoShooter]

cheesy!!! if you wanna try out a eotoech with a A2 site you can come over and shoot mine..

to remove the FSB take a punch and drift out the pins then remove your flash hider Lube Up the barrel with oil and pull the FSB off ive done this a few times(sometimes they are tight as hell) if you need any help im on unemployment so i have plenty of free time.

depending on who made it.. they maybe straight pins or taper pins

[Lycanthrope]

The FSB should be able to be tapped forward after the pins come out. You can use a block of wood and a light hammer tap. It HAS to go forward. It will.

As for the flash suppressor, you should see a crush washer or peel washer behind it if it's just threaded on.