No pins in ar 15 fsb?

[Guest vipergtsxz]

So I picked up a cmmg upper with a 20" pencil barrel a while back and I am wanting to replace the front sight with a low profile one. Am I crazy? I dont believe I have seen a fsb without pins installed on a barrel before. Is this normal? It shoots fine. How do I remove it? I cant seem to find anything online about it.

[c.a.willard]

It is most likely secured in place with some form of glue like locktite.  Try mounting it in a viced and heating it with a heat gun or torch

[Guest 6.8 AR]

Why don't you ask the outfit you bought it from? Could have been heated on, glued on. Might be better to keep shooting that one

and getting another barrel to play with add-ons.

[daveW]

Did it come from CMMG that way? I probably would not put a sling on the fsb...of course, you want to take it off so maybe put a sling on it.

[Oh Shoot]

There's gotta be more to the story -- surely you didn't get that directly from CMMG in that condition?

 

At any rate, should come off like any other unless it's freaking tack welded or something. Penetrating oil or heating FSB might help but, basically like this, except you don't have to worry about the FSB pins, obviously:

 

http://www.youtube.com/watch?v=uMG3IP2KH6g

 

- OS

Edited January 22, 2013 by Oh Shoot

[Dolomite_supafly]

New ones do not come with the holes drilled in them. All FSB's come that way. You make sure it is square and lined up correctly then use a jig to drill the taper pin holes. If you have one front sight it will likely not fit another barrel.

 

They forgot to drill for the taper pins. I would warn against trying to drill your own as it will likely end in failure.

 

Dolomite

Edited January 22, 2013 by Dolomite_supafly

[Dolomite_supafly]

At least it will make it easier for you to replace the block.

 

Dolomite

[Guest vipergtsxz]

I bought it from franklin gun shop. It was new. Supposed to be anyways. Looked that way was well. Is it normal for a manufacturer to do that? I'd like to take it there but its just been so dadgum crazy there lately and I'd like to try and avoid it if I can. I agree on not putting a sling on there if its glued on.

[Dolomite_supafly]

The only way to secure that is with taper picns. Locktite will not work. And the only way to install the taper pins is with the correct jig. Perhaps the shop doesn't have the jig and just installed it like that and hoped it would fly, BTW it won't.

 

If you are replacing is with a micro gas block I would not worry about it.

 

It is not normal and will come loose pretty quickly when you being firing it.

 

Dolomite

[Romad7]

If you are wanting it low profile to put a free float tube over it, you can just chop the top part off. That's what I did to mine.

Unless you find out it was done wrong then definitely get it fixed.

[Guest vipergtsxz]

I guess I'll try and contact someone at franklin gun and ask them about it and then maybe cmmg. I'm just wanting to put a scope on it. [quote name="Romad7" post="892243" timestamp="1358817237"]If you are wanting it low profile to put a free float tube over it, you can just chop the top part off. That's what I did to mine. Unless you find out it was done wrong then definitely get it fixed.[/quote] I agree

[Dolomite_supafly]

He cannot just chop the top off. The block is not being held in place by anything. He has no taper pins so chopping the top off will not fix anything. ANd trying to drill it yourself for taper pins is an exercise in futility.

 

I would recommend removing the front sight and selling it on Ebay. Probably going to bring some additional money because it HASN"T benn drilled.

[Guest vipergtsxz]

[quote name="Dolomite_supafly" post="892263" timestamp="1358818074"]He cannot just chop the top off. The block is not being held in place by anything. He has no taper pins so chopping the top off will not fix anything. ANd trying to drill it yourself for taper pins is an exercise in futility.   I would recommend removing the front sight and selling it on Ebay. Probably going to bring some additional money because it HASN"T benn drilled.[/quote] I definetely wont drill it myself nor chop it off if the fsb is attached improperly.

[Romad7]

He cannot just chop the top off. The block is not being held in place by anything. He has no taper pins so chopping the top off will not fix anything. ANd trying to drill it yourself for taper pins is an exercise in futility.
 
I would recommend removing the front sight and selling it on Ebay. Probably going to bring some additional money because it HASN"T benn drilled.

This is probably the best suggestion then get a low pro block rather than screw around with a questionable part. I retract my earlier suggestion. Don't mess it up so you can't sell it.

[Oh Shoot]

New ones do not come with the holes drilled in them. All FSB's come that way....

 

Sure, FSB's aren't drilled when you get them as separate part, but never seen any attached to barrel from manufacturer that weren't pinned.
 

Looking at the CMMG barrels onsite there that come with a FSB, they seem to be all pinned, like those from anywhere else:

Sounds like gun shop just minimally installed the various parts on it. Can't tell for sure that gas tube is pinned, but  looks like it is, need to make sure of that though.  Is there a flash hider on it? That'll have to come off too, if you're gonna replace it rather than have it drilled and pinned.

 

- OS

Edited January 22, 2013 by Oh Shoot

[Dolomite_supafly]

Yeah, they forgot to drill for the taper pins.

[TMF]

Ya, I'd take it back to the gun store you bought it from and have them get a smith to do it (on their dime) or send it back to the manufacturer. If you don't fancy the standard front sight block do what Dolomite said and just get a low pro gas block. Just don't shoot the thing until it is fixed. I'm betting after 15 rounds or so it'll shift around, and perhaps block the gas port or send gas escaping from beneath the block along with turning your AR into a single shot rifle.