I recently purchased a new M&P 15 Optics Ready. I got an awesome deal on it ($550 after rebate) but , of course, it has no sights. I really like the look of the basic A2 front sight, but right now I have the stock high gas block (same plane) as receiver (pictures below). I don’t really like my options of putting a front sight on that gas block, just looks weird to me., except for the magpul MBUS, but those are polymer and aren’t supposed to be used on the “hot” gas block. I know there are other front sight options, but none that appeal to me that much with my current gas block.

My ideal AR 15 would either have a:

1) Carbine length quad rail and the A2 front sight, an MBUS rear sight and an optic of some sort.  

2) 10” FF rail with same plane Troy folding front and rear battle sights, but that would still require removing my high gas block and replacing it with low profile gas block that would fit under the FF rail.

3) Combined gas block/flip-up front sight like this YHM Flip Sight Tower


So my question is how hard it is to remove the current gas block and install an A2 front sight or gas block/flip up sight combo? I can take off the flash hider just fine, but the current gas block does not appear to have a taper pin that can be punched out and I’m not sure how to remove it?  I’m guessing I would need to take it to a gunsmith.....anyone know the basic cost of having a gunsmith change out my current gas block with a standard A2 sight or the YHM combo gas/block flip-up sight? Let me know your thoughts on how I can get rid of this gas block!

I am far from an expert but that block is pinned and that will be a royal PITA to remove but it is definatley doable. If it was me I would get some folding sights ie.. Troy Battle Sight type and get a fore end that will go over that block or some type of two part fore end. Magpul has one and I saw this the other day....



MI two piece rail


I have absolutely NO knowledge of the quality of that piece.


Here is an extended version too...

MI extended rail


Removing that block is not a big deal but it is a pain. If you do your options are limited only by your wallet.

Also you need a punch and a BFH to remove that block... If you are going to completely replace it don't worry about messing it up.

I have to disagree It is no chore to remove and install a gas block if you know what you are doing..Read the link below and it will tell you everything you need to know.. I would choose option#2, go with a good rail of your choice.. and a low pro gasblock. I used a 9.0 Larue over a vltor low pro gasblock, with a LMT fixed front sight, and a Troy folding rear battle sight.. It is perfect for me..


http://www.ar15.com/forums/topic.html?b=3&f=4&t=226782

For me, option 3 would be the easiest. With no skill you can remove the taper pin from that gas block. Use a nail punch and punch it from left to right. Or, non ejection side to ejection port side. Purchase the Troy 2 piece quad rail from AIM as well as the YHM flip up front sight. From start to finnish, you are looking at < 1 hour of work.

ETA: Don't forget to punch out the gas tube roll pin. Don't destroy this one, you will need to use it again. Remember to buy a new crush washer. You will have to remove the flash hider and old crush washer. They can only be used once.

Thanks for the input everyone. It appears my taper pin on the gas block actually punches out from right to left (the larger head of pin is on the left side) , which I've heard is just a quirky S&W thing.  I'm leaning toward replacing the gas block with the YHM combo gas block/front sight and installing a two piece quad rail. I think the shorter quard rail look is what I really want. I think the YHM combo would be much easier than trying to install an A2 gas block/sight since there are no taper pins to mess with on the installation. Still mullling over options....feedback still welcome!

.

this is exactly the same situation I am in w/ the M&P15 OR that I just purchased.  I am not much on the railed gas block that comes on the rifle, I would actually prefer the look of the fixed front sight/gas block combo like the ones that are just about standard on all other AR's...Unfortunately from everything I'm reading this isnt an easy removal on these M&P's...I dont know if they are doing something different of not, but I've even read posts that some M&P owners had to dremel cut the block in half to get it off, almost like it was spot welded to the barrel or something???

I would love to hear first hand from someone who has removed this from the M&P15 OR specifically.  Also, something else I am curious about is if there are replacement gas block/sight combos that can be installed that will not require any special/custom work or drilling, etc.  Or if there are low profile gas blocks that would fit up perfectly without any additional work or drilling/tapping, etc, as I am considering putting on a mid length free float quad rail instead of the standard carbine length...

Is that a set screw on the bottom of the gas block as well??  Looks like it in the pic.

I would just leave it.  Put on a carbine quad rail and a LMT front sight on the block.

That gas block if WAY more secure than any bolt on front sight/gas block combo.

Yes, there is one set screw and one taper pin. I am thinking about just trying to remove that taper pin before I purchase any further rails, blocks, etc. I have finally decided what I want on this gun though........YHM Specter length lightweight quad rail, YHM end cap, low pro gas block, and folding front/rear sights. I feel comforable with the entire process of installing the FF rail except the gas block issue....and also how I'll perfectly align the new block on the barrel port. I'll figure something out. Maybe I'll just contact Smith about any weld issues and the stock gas block.

I just called S&W and they said the gas block on the M&P 15 OR is held in place by the single taper pin and the single set screw. There is no spot weld or any other factory process they use to keep this gas block attached. Also, he reitterated that the taper pin is removed out the non-ejection-port side, which is typically the reason some people "just can't seem to get the pin out!", because they are hitting the wrong side.   BTW- The customer service rep at S&W was excellent and told me to call back with  any questions. He said there are a lot of rumors "out there" that get a lot of people and their guns in trouble. I got them on speed dial now.......gotta love goof CS.

please keep us informed of your decision and how well the removal process goes, as well as how well the replacement block goes.  Will the replacement block match right up with the hole for the gas port?

If you can align the rail, then you can align the gas block.  Align the block the best you can, install the rail and see if the spacing between the block and the rail is equal (at the top where the gas tube is).  If not, take off the rail and adjust the block until they are equal.

UPDATE #1 (Pictures below)


Well, I finally decided it’s time to pull off that hideous gas block off my M&P 15 OR! Keep in mind this is my first AR 15 so I had no AR-specific tools before today. I went and picked up a 6 piece pin punch set (wal-mart has them for $10.00, I got mine at True Value for a couple bucks more). Also, I do not have a vice on my work bench yet. Here’s how it went:

1)Removed the plastic hand guards. Removed the BCG. This is necessary when removing the gas tube prior to sliding off the gas block. Laid down a blanket and placed two pieces of 2x4 on each side of the gas block to support the barrel. Supported the butt stock with some stacked work gloves.

2)Used a 1/8” pin punch and a big hammer and punched out the taper pin (REMBER: RIGHT TO LEFT. Smith does it backwards for some reason.)Took about 3-4 good solid hits and it moved half way out. I used the nail set (yellow) and easily knocked it the rest of the way out. I could have used the 1/16” pin punch to move it the rest of the way, but didn’t want to accidentally bend that little sucker before I had a chance to use it on the gas tube pin.Also, you may want to tape up the gas block if you plan on using it again. I nicked mine a little when the pin punch slipped off the taper pin once. I didn't care though because I won't be using this gas block again.

3)I then used an Allen wrench and easily screwed out the single set screw.

4)Used the 1/16” punch and easily moved out the gas tube pin.

5)I then wiggled the gas tube loose and pushed it out (into the upper receiver), cleared the gas block, then pulled it back out completely.

6)Took the large crescent wrench and put electrical tape on the teeth to protect the flash hider. I then easily removed the flash hider with a little lefty-loosey and elbow grease.

7)At this point I was already able to wiggle the gas block by hand. I sprayed CLP all over the barrel between the muzzle and the gas block. I tilted the gun on its butt stock and let some oil run between the gas block and barrel. I then wiggled the gas block completely loose and slid it off the barrel. Piece of cake….no scratches on the barrel at all.


Well, that’s it. This whole project took about 15 minutes, because I took my time and went slow. It was very satisfying….and yes….I am now officially addicted to AR 15’s. I will now order the YHM specter length FF quad rail (either lightweight or diamond, not sure yet), YHM end cap, phantom flash hider, YHM low pro gas block, and blackend gas tube. I will also have to get a vice, vice block, and armorer’s wrench in order to complete this project, along with a few other odds and ends like loctite, etc. I know these instructions are bit overkill for the veteran AR 15 enthusiast, but for someone out there like me, they should help a lot. Especially since there is not much information out there on the M&P 15 OR gas block. I will provide more updates and pics when I get the FF rail and tools in. It may be a few weeks, but I promise I will update.


All the tools I used (and the flash hider/crush washer).
http://farm5.static.flickr.com/4110/5022805313_95dd4918e9_b.jpg



Barrel, gas block, gas tube, taper pin, gas tube pin, set screw, hand guard retainer "thingy".
http://farm5.static.flickr.com/4090/5023415198_1716ac5421_b.jpg


http://farm5.static.flickr.com/4087/5023415860_63bbd623aa_b.jpg

See nothing to it.... I had a set of them Dasco punches and they didnt last they were too soft and bent took them back to get money back. Might look at Spikes tactical for the vice block set, it is a pretty good one from block Worxx..  I recently purchased a set of punches from BCM, used them once and they seem to be holding up.. I had a YHM light weight, and loved it, I have since replaced it with a Larue, and like the feel much better of the larue than the YHM. The YHM is good for the price though.. Good luck..

Thanks for the posts gentlemen, I am doing this tonight to install a 10 DD lite rail and low profile gas block. That whole right to left  curveball is somewhat annoying. And a setscrew too? Weird.

Thanks for the heads up, this is why ARFCOM rocks.

I think I am going to remove the setscrew first perhaps to relieve pressure on the pin.

Hey just wanted to say thanks for posting information on this and pictures, I replaced my M&P-OR gas block with an A2 FSB this weekend and your posts helped a lot.  Still had to cut the gas block in sections to get the taper pin out (tried drifting it out in every way possible for 3 hours and just gave up), but at least I know I was pounding in the right direction the entire time :)

Awesome, glad it worked out for you. I put a link below to another post where I put a couple pictures of the rifle after I installed the new YHM gas block and YHM Diamond rail, Phantom FH, Badger Tac Latch, and Hogue Grip. I highly recommend the YHM low-profile gas block for any future free float builds you may encounter, and another guy put some great instructions on this link for making sure it is installed perfectly. Now I'm just waiting on some iron sights and I'll be done....for a little while at least :)

http://www.ar15.com/forums/topic.html?b=3&f=4&t=515213