View Full Version : What kind of pain am I looking at to remove the FSB from a S&W M&P barrel? UPDATE
Hey guys,
I'd like to shave the front sight on my M&P Sport, as part of a free float rail install.
From my research, it looks like on some guns the sights come off fairly easy, and some are a royal pain.
Anybody done the work on M&P barrels?
How hard was the sight to get off, and then back on and lined up again?
Thanks in advance.
The depth of knowledge on here is amazing.
UPDATE:
Decided I wanted to try to get the sight off.
Wow!
I tried everything:
Heat, large punch, cupped punch.
I clamped the barrel to my bench.
Tried it on a concrete floor with the wife holding it.
Those pins did not budge!!!
Fortunately there is now a shop in town that works on ARs.
Twenty minutes and twenty dollars later, the pins are out and the sight is off.
They were really on there!
Read this (https://www.m4carbine.net/showthread.php?41732-Removing-BCM-FSB-Taper-Pins).
S&W's pins are tough... tougher than my BCM pins. I don't recall if they went the traditional direction (I've read they don't, but I just don't remember), but you can just look and see the large end. The instructions in the link above will get it done, but you need to have a friend and you need to use the right punches. I made wood support blocks instead of using action blocks.
The pin holes will realign it fine, and it just needed some soft taps to remove from the journal.
Don't take it off. Cutting off and shaping an FSB by anyone competent enough to use power tools, can be done completely in place. I've done several by cutting them off with a Dremel cut-off wheel, and finishing them on an upside down belt sander clamped in a vise. I have also done them by finishing with 4 1/2 grinder and a flap sanding disc (google it).
Of course, if you need to remove the barrel nut for your desired hand guard, you can completely ignore my advice.
I've removed a lot of FSB's over the years, for myself, my friends, and friends of friends, but I recently ran across the first one that I haven't been able to remove, S&W M&P OR factory gas block. It belongs to my buddies girly friend. It's completely stock and she bought a KMR that we were going to install. We tried for over an hour and a half with progressively bigger hammers, multiple punches, a torch, and PB Blaster. I was pretty bent that I couldn't get the thing off to be honest. That was in May, and to this day, nobody has got that single pin out. Beats me.
I've removed a lot of FSB's over the years, for myself, my friends, and friends of friends, but I recently ran across the first one that I haven't been able to remove, S&W M&P OR factory gas block. It belongs to my buddies girly friend. It's completely stock and she bought a KMR that we were going to install. We tried for over an hour and a half with progressively bigger hammers, multiple punches, a torch, and PB Blaster. I was pretty bent that I couldn't get the thing off to be honest. That was in May, and to this day, nobody has got that single pin out. Beats me.
As I alluded to earlier, I've read a good bit of speculation on S&W pins. One thing I've read is that they're press-fit. No idea if that's the case, but if you've got a shop press, it should move it regardless, but that would explain it. If you've got any AK friends, most self-respecting AK guys will have a press.
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Thanks for the link and the advice.
The last thing I want to do is butcher my gun and have to wait while I order more tools or parts.
I have read before that S&W FSBs can be a bear to get off, and it seems like this confirms it.
May just stick with the Magpul forearm.
Thanks for the link and the advice.
The last thing I want to do is butcher my gun and have to wait while I order more tools or parts.
I have read before that S&W FSBs can be a bear to get off, and it seems like this confirms it.
May just stick with the Magpul forearm.
I ended up putting a Midwest FSP handguard on mine. Just Dremel off the delta ring, and bolt it on. A bit heavy, but functional.
https://farm6.staticflickr.com/5802/20480473348_337c40a5c6_m.jpg (https://farm6.staticflickr.com/5802/20480473348_a62d7966c0_o.jpg)
I did a BCM upper without removing the gas block. I put the upper in a clam shell and then vised it. I put multiple layers of duct tape on the barrel around the gas block for protection. I hacksawed the top off and sanded and shaped it with sanding wheels on a Dremel and files. Shot it with flat black BBQ paint. It's not that hard, just think it through and pay attention.
You know what? I completely missed where you said you wanted to shave the FSB... I read "save", not "shave".
I've not shaved an FSB on the barrel, but I have done it off the barrel, and it's an easy job. I didn't bother making it clean or symmetrical, but a Dremel, a grinding wheel, and some cold blue did the trick. Took about an hour or so from start to finish.
If you don't have to change barrel nuts for your desired handguard, then TomMcC and AKDoug are right on... just do it with the FSB on the barrel.
bullittmcqueen
08-24-15, 17:15
I removed a FSP from a sport for a friend, and it was a pain. Pins weren't as tough as my BCM's, but far from easy.
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
09-24-15, 21:21
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
09-27-15, 09:48
This tool and a BFH.
http://www.brownells.com/gunsmith-tools-supplies/rifle-tools/pin-tools/taper-pin-starter-prod26485.aspx
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.
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.
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?:D
Don Nguyen
09-30-15, 16:52
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
09-30-15, 18:06
+1 for chopping it. A chopped factory FSB makes for the most low profile, secure, strongest gas block possible.
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-36-in-Heavy-Duty-Bar-Clamp-3736-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):
http://i1308.photobucket.com/albums/s609/tomfiglia/Mobile%20Uploads/image_zpsllppr4d6.jpg (http://s1308.photobucket.com/user/tomfiglia/media/Mobile%20Uploads/image_zpsllppr4d6.jpg.html)
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