Quick Tip: How To Remove AR-15 Front Sight Gas Block Pins

For some folks, today's subject is tricky to pin down, but don't worry! Brownells Gun Tech™ Caleb Savant shows us how to remove the pins from an AR-15 front sight gas block assembly. The task sounds simple, and really it is. But if you don't do it correctly, you can damage the gas block or the barrel. The pins go all the way through the gas block and through a channel cut in the exterior of the barrel. The channel anchors them to prevent the gas block from shifting under recoil. The pins are tapered, so they go in and out only ONE way. You push them out from the SMALL side.
TOOLS FOR THE JOB: Safety glasses, of course! The Brownells AR-15 Bench Block is super handy in protecting both the gun and your workbench top from damage. One side is for removing the gas block pins and the other is for installing them. Caleb has his handy set of Starrett punches, though only two sizes are needed for this job. A brass-nylon head gunsmith's hammer is a little light for this task. Caleb prefers a standard ballpeen with a little more heft to it.
FIRST CRACK: Press the barrel and front sight gas block into the "PINS OUT" cutout on the bench block. To apply as much mass and energy to the pin as possible, use your largest punch. The ends of the pins are rounded, so a small punch will slip off and ding the gas block or the barrel. Hold the tip of that big punch securely on the pin, making sure the punch isn't touching any portion of the gas block. Hit the punch with the hammer until the pin's tip is flush with the surface of the surrounding metal.
THE REST OF THE WAY: Get a smaller punch that matches the diameter of the pin. (Caleb is using a 1/8" punch.) Tap it lightly with the hammer until the pin drops out. Because the pin is tapered, it will move more freely the farther you push it. The gas block should be pretty loose. You may need to wiggle it a bit to fully break contact and slide it off the barrel.
TURNABOUT = FAIR PLAY: The installation steps go in the opposite order, except you'll need only the large punch. Putting the pins in is easier than taking them out.

[@CalebSavant]

If you want a link to every too used, go check out this video in the Trigger Times section of our webpage! Oh also, no I do not like using cup tipped punches for this task, I find that they do not transfer enough energy to do this effectively on the more stubborn pins you sometimes run into.

[@robotbuster1487]

@@TettyBoyFloyd A gunsmith with a true machinist experience, and a Bridgeport w/Digital Read Out unit, can pick the original 2 pin holes in the barrel. Make note of the locations using the Digital read out. Slide the new FSB into barrel , put it all in a special clamping jig bolted to the Bridgeport table. Drill,then taper ream That's a brief description. I've left out a few steps. Oversized replacement pins may be needed. Some of us remove FSB taper pins with a hydraulic arbor press.

[@bradd8383]

Can we get a video of the blackout defense barrels

[@juniyananajukyu]

Caleb, did you have to re-zero your irons afterwards?

[@raffieb762]

I need to switch out barrels for my sp1, so what you are saying is the barrel has to be drilled? They don't sell barrels pre drilled?

[@raffieb762]

@Jared Kikeman I don't have the equipment or experience for all that haha, thank you! Big help

[@LILJ830]

This guy is like the Bob Ross of firearms.

[@psycopaintball22]

Just beat the devil out of it!

[@frankbrowning328]

Excellent point on using the large punch. It isn't often you find someone that is not a Gunsmith that knows the proper way to remove a round top tapered pin. I learned this back in Gunsmithing school decades ago and when people 1st see me do it they nearly all ask why I'm starting with the large punch

[@SmokinCoyote70]

I'm not a gunsmith and I knew that but there's a lot of things I don't know about the AR platform I can field strip it clean it and shoot it . I was in the army but they really don't go into to much detail about the workings of the rifle . I'm a AK guy but I do own an AR and it has a pesty front sight post sticking up that I want to remove lol idk how to do it or what gas block I need or what kind of handguard to install afterwards

[@Usicky12]

@@SmokinCoyote70 then why did u buy an AR with a front sight post? lol

[@shawnparrish1999]

More videos like this, please. Good straight forward instruction with years of experience behind it.

[@murphymmc]

Great tip. Let's have Brownells develop a punch that has a matched radius concave tip expressly for those pins, like a nail set with an 1/8" tip, but straight shank. That would nearly eliminate any "slippage" off the pin head while impacting. You could get rich, Caleb.😏

[@MR619Can]

they already have and he mentioned it in his comment = cup tipped punch. he doesn't like to use it. I have used both techniques and for the infrequent armourer who has to do this once every year or 3, the method he showed in the video is the best way. YMMV

[@The-CryDreamer]

I’ve never seen better instruction on the nuances of the way to hold the punch and finessing the tools any better. Absolutely top shelf instruction. Thank you.

[@pole_barn_builder]

Caleb, i promise, no hair joke. It would be cool if you did a video on how you got into gunsmithing and some more of your background with guns!

[@feez357]

What do you mean - no hair joke?!! I would LOVE to have his hair!! I might wash the grease out and trim the sideburns a little but it would be better than my ugly ass bald head.

[@jmpetersrn]

I just wish I HAD hair. 😢

[@wejones426]

Loving the AT-4 in the safe😂

[@robdavidson4945]

Thanks for the tutorial. The orange bench block makes this faster and easier.

[@KuntryBoy4Lyfe]

Thanks for the video! I have always avoided barrels with fixed front sights like this because I didn't want to mess with them if I decided to go free float. I feel confident I can "knock it out" now if I decide to change it up, lol.

[@sluttybutt]

Don't feel too confident. Some manufacturers go absolutely apeshit in their assembly process and even veterans have been defeated

[@rodgersmith1573]

Fixed front sights are becoming less and less common as free float handguards are taking over, as well as the time it takes to actually drill and ream for the taper pins on the A1 and A2 front sight/gas blocks. In other words, if you come across a barrel with one installed, you ought to leave it be, and find a barrel without the aforementioned work done to it for free floating purposes.

[@KuntryBoy4Lyfe]

@rodger smith Yes, that's true, but the reason I wanted one was simply for the "classic" look. I'm just glad to know I can take it off myself if I decide to put a free float on.

[@toddparsons2980]

This was exactly the tech tip I needed as I have been wanting to do this but have been reluctant. Thanks.

[@aintgonnaworrynomore]

Thanks for the tips. Got the front sight bench block yesterday. I was having a devil of a time.

[@gadsdenjim8785]

I like using a appropriately sized Nail Set to initially get the pins moving. I got a couple that are the perfect size that hug the rounded tip of the pins. No slipping off. Works good for driving them in too.

[@jamespilbeam209]

As usual, Caleb explains and demonstrates in a no-nonsense manner. Thank you!!😊

[@afroghair6793]

Thank you Brownells for this psa.

[@lawman5511]

Have not done this in 20 years. Great refresher!

[@bobdole234bd]

Thanks for taking the mystery out of this process

[@wittsullivan8130]

One time my son bought an AR Stoner upper receiver from MidwayUSA on sale that was a really nice price. He couldn't get it to zero with irons, in fact, the front sight pin was coming out and it was still shooting high. As it turned out, they installed a standard height front sight tower onto the flat top upper instead of a tower marked with an "F" for flat top. After MidwayUSA customer support told me, "I don't what we can do about it, usually customers just slap a red dot on it and they're happy." My son went to a local shop, bought a correctly "F" marked tower. He had no problems removing the flash hider and front sight tower, but the holes on the new tower wouldn't line up. As it turned out, whoever drilled the slots on the barrel for the taper pins drilled one of them at an angle and then drilled holes to match on the original (incorrect) front sight tower, so no other sight tower would ever fit right using the slots and holes. Evidently the guys at MidwayUSA and AR Stoner don't give a crap, they're just cranking 'em out with the wrong components. I was raised if you're going to do something, do it right. If not for personal pride but to prevent a customer from having problems, which end up as your problems, costing money to fix for no good reason. It's no brainer to see if the front sight tower had "F" on it when you're building a flat top upper and drill it straight. Anyway, the guy at the local shop did unholy things to a rollpin to make it fit the angled slot. It works, but it looks janky. I never received a reply from Mr. Potterfield about it.

[@rodgersmith1573]

Every A1/A2 pinned front sight block is going to be UNIQUE. The way in which it is drilled then reamed allows for variances between them all. It's considered to be a permanent modification to the barrel and does not need compatibility across all front sight block/gas blocks. Yours is a very special circumstance which should've been handled by customer service and warranty work. I also agree with you that they could have done more to ensure it was an "F" marked front sight block, but since your modification looks so janky, knock out that roll pin and the remaining taper pin, remove the sight block, break free the barrel nut torque, remove the upper receiver, replace with an A2 upper receiver, re-install barrel nut (30-80 FT-LB. torque value), re-install gas block with taper pins, and run some A2 shiny, slim handguards. Install rifle receiver extension and A2 spacer, A2 buttstock, and A2 pistol grip. Voila! Retro rifle! Next, begin assembly of high speed, low drag Gucci rifle using the A3/A4 flattop upper, and begin with a barrel that is not pinned. Unless you want pinned. In which case, get yourself something like an FNMI CAGE code barrel (if you can find it), FN America Cold Hammer Forged barrel, or something of that nature. Stay away from the Stoner shit. Just 'cause it says Stoner doesn't mean Eugene Stoner had anything to do with those parts produced nowadays.

[@wittsullivan8130]

@@rodgersmith1573 You have to be kidding. You're telling me to upgrade a $200 upper with over $X00 worth of parts? I know "ARStoner" is just a name, just like Armalite, and even Colt rifles aren't the same as they were 30 years (or more) ago. I was banking on MidwayUSA's reputation and they failed me. Any person worth pulling the handle can drill straight, not at a 15% angle and I hope they can see there's no "F" on the part that's matching up to a flat top.

[@rodgersmith1573]

@@wittsullivan8130 I am SUGGESTING you do the aforementioned upgrades because you've currently got one roll pin which doesn't belong, and the only thing to make it 'look' right would be to return the non F-marked FSB to your barrel, thus giving you a sight meant for a carry handle. That would then leave you with your flat top upper with which you could spend a bit here and a bit there over time until you've got a completed rifle. Or, keep running the roll pin and the 15 degree angle F-marked FSB... It was merely a suggestion.

[@maxwelltodd7757]

I use a more solid surface, an anvil, as a base to drive the taper pins in and out. Works better and faster.

[@pb68slab18]

As a toolmaker, I hate taper pins. Most people use a flat punch when the ends are not flat. Using a flat punch on the rounded small end of a taper pin usually flares it out a bit, turning into a rivet!

[@1BXB]

As always learning from your right-to-the point videos. Thanks!

[@hoosiered471]

Great instructional video!!! Thanks!!!

[@loboloco866]

Excellent review, outstanding thanks Caleb.

[@davidhalldurham]

Thank you, Caleb! Excellent video!

[@BenRivered]

Awesome, Caleb! You made that look easy bro. Nice video. Thanks.

[@anon135]

always enjoy the vids. Thank you...

[@ianalderson5133]

If you're having issues the only answer is a larger punch, a 2-3lbs hand sledge, and a non rebounding surface. Not concrete. Not plastic. Wood or iron backstop

[@glockparaastra]

Great demonstration. Thanks!

[@flea-kh7om]

Yep, same way I've been doing it since 1972. Great job Caleb

[@GregsGruns]

Great video, Caleb. I have a slightly different block and I have never had the pins come out as easy as you did there... then again a lot of times I'm messing with crusty milsurp parts. Maybe I need to get one of those blocks...

[@jimhurstjr]

Thank you so much for this video😊

[@rodneyobrien4624]

Just did mine on the M&P sport 2 and man they were tight!!!! Heated them up a little and it helped, also used a tapered punch…thanks for the video

[@Beanmachine9198]

Good stuff as always, from our S. Louisiana man💪💪

[@RonWayneOfficial]

Great stuff! Subscribed. 🤠👍

[@danefoss9679]

Great video

[@25centsapop]

Third time I've subscribed to y'all Thanks for another great video

[@Beastmaster6actual]

Love the AT4 in the safe

[@Hero1117a]

Excellent

[@billhatcher2984]

Thanks that's a good tidbit I don't work on them much but if I need it I will know thanks again

[@seanrhone5306]

I really need a safe with a AT4 as well!

[@Black5Delta]

Great video, Caleb. Maybe I've missed it, but have you done a video on correct gas tube lengths for different barrels or suppressed barrels? Very curious about building my own upper soon.

[@mistert51]

A couple of months ago I had purchased one of the A1/retro 10.3” barrels from the site to do a “MK18 Mod 0/CQBR Block I at home” build and attempted to remove the FSB to install a Carbine length KAC FF RAS rail and I could not get those pins to budge. After about 30-45 minutes I did manage to get one of them out, but the other didn’t move at all. I ended up admitting defeat and reinstalled the one pin and went with a KAC M4 RAS instead. The FSB now forever bears the marks of my frustration lmao.

[@James-fs4rn]

👍 thanks for sharing. Bet this will save a lot of beat up parts.

[@texas66]

More mass is most important, in fact you need mass on both sides of the block. If they don't break loose with those baby taps on the bench, get twice the hammer and put it on a bare concrete floor. Make triple sure you're striking the small side and say a short prayer to St. Stoner while you're at it!

[@happyhome41]

FANTASTIC !

[@abolishtheatfandrepealthen6963]

Good stuff

[@scottmahony4742]

Thanks man! Got em!

[@caseyfoster710]

New Sub here. great vid, thx, it was exactly what I was looking for!

[@ETHRON1]

I have a specifically cut block of wood I put under the chamber end of the barrel to stabilize it...because it is a pain fighting it...as a rule of thumb, after you get one out the other is a piece of cake...usually.

[@tangolima6462]

Good video, I always soak the pins in AeroKroil before I remove them. I’ve never had to double tape the punch to break them loose. Also the largest Starett punch is good for peening a M1 barrel where the gas tube interferes.

[@ezrabrooks12]

Good Job!!!!!

[@johng1902]

Thank you. 🙂

[@LilYeshua]

Use a gas block pin punch with the special shaped punch end that keeps the pin from mushrooming and follow Caleb’s instructions and use a solid surface to bang on.

[@hectorperalta8787]

Can we talk about the bazooka in the safe lol

[@g54b95]

"...because eyeballs do not grow back." Most intelligent thing I have heard all year.

[@BravoJulietAlpha]

Very good

[@johnb3616]

So if you chose to put a low profile gas lock on and gas tube do you just cover the holes that were made for the pins or is there something else that needs to be done to ensure the gas block set screws stay in place with those holes….such as using the holes for dimple spots if that makes sense to you?

[@wagon9082]

Wonderful Video. I would like to learn about drilling the barrel for Gas Block Pins. Online people talk about using vise grips and such. I also have not found a good fixture to fixture this.

[@brownells]

Caleb has a secret tip he'll share in the near future.

[@wagon9082]

@@brownells i am very much looking forward to that. :-)

[@hphillips7425]

I like the how too video. What are the dimensions of the tapered pins

[@Redsox247]

👍 Thanks I like these videos

[@janssenmoen953]

I like the AT4 in the safe 😅

[@ryanthorne5432]

Kroil, or other good penetrating oil, can help the pins get moving.

[@mattfleming86]

A gentle blast on the block itself with a propane torch can help too by expanding the metal on the block (you do not want to heat the pins.) It also helps your penetrant creep in a little. It doesn't take much heat to help. I've only dealt with a REALLY stuck pin once. Usually they come out the easy way... but there is always that one.

[@joed7593]

What causes the pins to back out on their own? Thanks for your input

[@alexcasaresOracleAZ]

Do you guys have a video showing how to install this type of iron sight onto a brand new barrel that doesn't have the notches?

[@Timber_LXG_5]

a pinned FSP is my favorite gasblock

[@carloschaparro2413]

Bros casually got a rocket launcher chilling in the safe 🇺🇸🦅

[@brycetrezise8792]

Can you get a LPGB that will fit the pin holes?

[@mrshort2379]

great content great tip: you made that look easy. now all I nee is for you to show me how to fix my trigger reset. when I pull the trigger, and then go to slowly ease off to reset, it fires again, but it only does it when I slowly ease off the trigger to reset. if I just let of the trigger it resets no problem

[@navywolf1753]

Sounds like a disconnector or disconnector spring issue

[@ChaohsiangChen]

It would be nice if Brownells can show us how to assemble a faux dissy barrel.

[@jimmywilliamson8540]

I had been wondering for a while. I might actually put mine back on. I'm just not a big fan of the four sided Cheese-greater hand guard that came with my low mileage AR.

[@johnphillips222]

Here are some additional tricks with the taper pins for the FSB. 1) Use an inductive heater to make the FSB pretty warm. That thermally releases the taper pins. 2) Use a tapered, cup tip punch. 3) Place the punch block on a concrete surface or super solid bench to better eliminate the bounce. 4) A 24 or 32 ounce ball peen hammer seems to work best. At work we use an inductive heater and a hydraulic press with a cup tip to do this work. Not everyone can afford that setup.

[@S1L3NTG4M3R]

thanks

[@jesusrivera8909]

BCM pins are really hard to get out nicely, so I channeled my inner bubba and used a Dremel.

[@skullofserpent5727]

Good morning America!

[@ethanladymon6760]

What additional steps would need to be done to straighten the FSB? I have a barrel where the FSB is off vertical by 1/8 inch or so and I don't mind trying to fix it myself.

[@derek45auto23]

Sabre defense pins are backwards....they made really nice barrels

[@ralphjohnson8775]

I ues a 407 3/8 mayhew punch and a 2lb hammer 🔨 With a wack or 2 they will move. Then I use a smaller punch just to push them out by hand.

[@5jjt]

Do taper pins ever walk free? Since they are friction/press fit, should we use Loctite or Rockset on installation of the taper pins?

[@PureCountryof91]

This will be important when I build the 6.5 or .243 that I want from a piston gun..

[@stearnbrown3846]

I want to add a free floating hand gaurd. I know I will need to replace Gass block with a low profile one. Any recommendations?

[@mrouija25]

Now i just bought a retro barrel from you guys (brownells) and the front site is very canted to the right side! Now i ordered new pins and was going to try to remove the old pins and straighten the front site block. I tried what your doing and was beating the you know what out of them and they will not budge, and yes im driving them out the right way, do you have any helpful ideas?? Please help! Thanks

[@donsal.t.1765]

If I want to change my barrel to another receiver do I have to remove the gas block/tube as well?

[@linkbond08]

And here I was breaking out the cutting torch.

[@johnstaton4302]

Are the tapered site pins opposite each other on the front site gas block removal?

[@danielrobbins5834]

I always measure the pin ends first to determine direction of taper. S&W M&P’s sometimes have the pins going in opposite directions.

[@tylerbarnes4806]

I found out the hard way after I snapped the tip off my punch taking the gas block off my S&W. Make sure to measure first!

[@ETHRON1]

I know one you won't get out with a punch...unless they've changed their process.... CMMG, they hydrologically press the pins in and they are not Tapered like normal pins. In case you are wondering, I got that from them. A video I did along time ago I broke 3 punches before I called them. I had to cut the A2 block off or send it to them...

[@some_cool_random_guy]

i love your haircut

[@bunnyoperator]

Facts. 🤣 Coincidentally, I recently released a vid on the Centurion Arms CMR cutout handguards that require manipulation of the FSB. I'll link this vid in there for the folks that need it.

[@SmokinCoyote70]

I have a 20in heavy barrel with a front sight post on it . I wonder if I can remove it and install an .936 adjustable gas block on it ? Or do I even need a new gas block ? Is the gas block built into this front sight post ?

[@rustynail246]

Nice job on this one, I mean " this one". Now try the other ones that the pins were pressed through in the factory such as Adams Arms gas block and Olympic Arms.

[@sixoffive]

brass ball pen hammer, brass punch or steel punch if needed

[@actionjksn]

I would like to have a jig that would allow me to drill these same holes for a low profile gas block. I think they make something but it's pretty expensive. Basically put it in place with the set screws and then drill the taper holes and pin it. I'll probably never do it but I would like to. I'm sure it's a lot of work and harder than it looks

[@killersp1974]

Better off to just have a Gunsmith do the job for you; piece of mind is a great thing. Nnothing worse than a sight post that's crooked or the reaming of the 2-0 pins that are too deep and 1 sticks out too far.

[@actionjksn]

@@killersp1974 What does a low profile gas block have to do with a sight post? I successfully machined an 80% steel frame 1911 with a hand jig I doubt that I need a a gunsmith if I had a jig for this.

[@davidschaadt3460]

I tried it ,I wanted to replace a slightly rough barrel nut but it wasn't to bad .But without getting to aggressive I gave up .The nut wasn't that bad.

[@okaythisisepic6413]

Hey Brownells, help some of us out here. Do these work with the retro barrels from Brownells and PSA?

[@realtyrocks1969]

Do you need to replace these pins when putting back on or can you reuse the pins?

[@gonzaleg165]

Do you have to take the barrel off to remove the gas block and install another one? Can the whole thing be done with everything else still assembled?

[@sparkyfister]

"Eyeballs do not grow back" Sure buddy, believe the government lies! 😂

[@brandojaco]

My grinder didn't struggle lol. Came right off without any damage.

[@dragonsofthunder]

Facts

[@blantant]

My grinder worked after many curse words and failed attempts at punching it out. Didn't realize i needed the big punch

[@memesarentfunny2248]

wtf

[@Sandshredder2]

The mystery has been solved!

[@charliecharles4571]

If I remove the gas block sight from my manufactures barrel, should I buy a new barrel for an aluminum hand gaurd? Or can I buy an aftermarket gas block to fit inside the drilled areas inside the new hand guard on the manufacturers barrel?