What kind of pain am I looking at to remove the FSB from a S&W M&P barrel? UPDATE

[opngrnd]

I removed, shaved, and reinstalled the FSB from a S&W M&P15 earlier this year. It had approximately 3000 rounds through it at that point. The pins weren't super easy, but using a punch that has a concave tip made it doable. In my case, the pins were backwards to what I read BCM is, and were also backwards according to the Brownells FSB Armorer Block. Having a buddy help hold the upper was a big plus.

Since I had it off, I installed a Black River Tactical Custom Tune Gas Port to address the barrel being overgassed. It wasn't requirement, but sure did make an appreciable difference.

[buckshot1220]

I've done some gnarly ones before. My trick is I use a massive (like 1/2") brass punch and mini sledge to start moving the pins. Using the brass guarantees that you won't mushroom over the heads of the pins whereby preventing any chance of an easy removal. Once the pins get moving I switch to the correct size steel punch. Also, I wrap most of the barrel and FSP in a few layers of painters tape and sandwich it between two pieces of wood similar to those that come on a pallet. I then clamp that to my workbench. Only the portion for the pin I am working on is accessible so the barrel remains supported.

When I finish I simply run the brass punch on a belt sander to get it square again. I'm sure in due time I'll have to buy a new one for lack of material.

[Slvr Surfr]

This tool and a BFH.

http://www.brownells.com/gunsmith-to...prod26485.aspx

[mini14jac]

Update in the OP.
According to the tech at S&W the front sight isn't put on with a press.
It is installed on the barrel and then the holes are drilled in the sight and barrel at the same time.

[SteveL]

Update in the OP.
According to the tech at S&W the front sight isn't put on with a press.
It is installed on the barrel and then the holes are drilled in the sight and barrel at the same time.

I think that's how all FSBs are installed.

[cd228]

Update in the OP.
According to the tech at S&W the front sight isn't put on with a press.
It is installed on the barrel and then the holes are drilled in the sight and barrel at the same time.

That explains the holes and how they lie up, but what about the pins? Are they driven in with a punch and a hammer one by one?

[Don Nguyen]

The worse is when one pin goes out easily and you expect the second one to have the same results, but then it becomes a nearly impossible mission trying to get the second one out.

I am not a gunsmith, but I always believed you gotta start learning a skill from somewhere, so I decided to remove the FSB pins myself. One pin ended up being so hard to remove that it basically deformed before even budging, and I ended up having to just drill it out.

[HansTheHobbit]

+1 for chopping it. A chopped factory FSB makes for the most low profile, secure, strongest gas block possible.

[TF82]

I've done two now, a Colt and a BCM and I've had great success with the following method. I placed a small block of 2X4 on my bench then used a clamp to clamp the front sight base and the block to my bench so that the pins and barrel were hanging off and the triangular part of the FSB was attached to the block. This requires a real, no BS clamp like this Jorgensen Heavy Duty Bar Clamp http://www.homedepot.com/p/Jorgensen...6-HD/100134583. In the case of the Colt and BCM I did this so that the muzzle is facing toward my right, but I think S&W has to go the opposite way (don't quote me on that). I then used a 5/8 punch and a mini sledge to get the pins started, once they move I use the proper size pin, the size of which I can't recall at the moment. The clamping method proved to be rock solid and after a few strikes they were free on both barrels.

Forgive this really horrible illustration, but I don't have any FSBs to mock this up with. It looks something like this (in reality the clamp should cover a lot more of the FSB):