A possible word of caution- I pinned an AR10 308 Criterion "Hybrid" barrel and wondered why accuracy was far poorer than the sub MOA Criterion expected. Long story short: After sending the entire upper to them they believe side pinning created a "hot spot" and/or change in barrel harmonics. I was getting 3 MOA with it side pinned and sub MOA after removing it and replacing with a non side pinned block. Much to my shock and pleasant surprise, Criterion sent me a NEW BARREL even though I pinned the first one. The new barrel was simply dimpled as they recommend. Comments and thoughts welcome. Outstanding service by Criterion.
I did the exact same thing with my 14.5" Criterion .223 Wylde barrel, though I suffered no loss in the accuracy department. Used a Geissele rail/gas block and sent it to ADCO for a "bomb-proof" installation of the gas block which involves pinning and 2 set screws. I think the biggest thing is to have it done by someone who really knows what they're doing. Can also vouch for Criterions customer service. I have yet to find a better company to do business with in the firearms industry.
@@robertsalas3984when metal heats up it expands the thick of a barrel greatly negates this but the area near the bore thats been drilled is obviously thinner which causes that entire effected area to be out a whack with the rest of the barrel. Think of it like driving fast on iced roads and then going over a speedbump. Thats why i just leave it at dimpling.
I compliment you sir on your instructional videos. There are many of these videos and I feel yours are second to none. You encouraged me to do my own build. Thanks.
I used to always pin my blocks. When i got into 3 gun and started using clamp on adjustable blocks I didnt pin those. As the years went by and i put thousands of rounds thru my 3 gun rigs in comps, classes and practice I never had a single problem with the GB moving, I started to think it was just overkill. I can def understand it for peace of mind and confidence though.
I used blue loctite one time, and loctite spread behind crevices of the gas block due to my over excessive use, and it pinned it so hard, I had to use the hammer to remove the gas block, and that's after heating it up with blow torch for good minute. Yet it didn't work, I had to put my upper (without BCG) into the oven at 350 F. Well...then I finally got it off. Don't overthink it, don't use too much loctite, but I would dimple the barrel for safety, as I did. But that will likely void your warranty. So yeah.
@@righteousone8454 How much loctite did you use and Where'd you apply it? I ask because I removed one setscrew from the one that's dimpled, from a complete upper I bought, then put loctite on the screw and reinstalled it. Am I anywhere near what you did?
I would highly recommend using a T handle rather than the drill for reaming for the taper pin after drilling. It is much easier to keep the taper from going out of concentricity when you do it by hand.
Even dimpling the gas block robs some accuracy. I have a comp build that is built for accuracy. The set screws on the gb are threadlocked. Thats it. Multiple comps and thousands (4900) of rounds later, no problems, no misfires, jams, etc
Seems like a great idea. When I free floated one of my AR's, I kept the A2 front sight/gas block, but I cut the site off and grinded it down, then reinstalled. I know people mention all the time if I wanted to convert it back I couldn't, but I don't plan on converting it back and A2 front sight/gas blocks are easy and cheap to get.
I'd like to to do this on my barrel, but my barrel is nitride treated. I had a hell of a time even getting it dimpled using BRD's dimple jig. To give you an idea how hard nitriding is, I wore a cobalt bit out against it before I got even a quarter of one dimple formed. The barrel *laughed* at regular steel drill bits. Regular steel bits, you might as well have been drilling with tissue paper. In the end, I had to get a carbide tipped bit from MSC industrial, and even then it was not easy. I shudder to think about trying this on that barrel.
jamesp81 nitriding is just a surface treatment of the steel where nitrogen is introduced to the molecular structure of the steel. Once you break through the surface it's unhardened for the most part and should be easy to drill
Reamed slightly too deeply, but still effective. Good instructional video. I build these for a living and this is bar none a constantly overlooked yet ultra-important step in creating a reliable AR15. Good video, sir.
Should the pin be flush with the freshly-reamed hole on the other side (the opposite side of the one he's drilling from in this video) when you start to hammer the pin in?
Der Fliegende Holländer It's relatively inconsequential regarding the pin starting position, so long as it's driven in an appropriate depth to engage the taper fully. That can only be gauged by the installer. Hard to see in a video. Some systems use self locking roll pins and can be equally as effective. Easier to drill for, too.
I have the same taper jig and it works great......I have the benefit of using a drill press......I have a different style jig also which lets you pin using a coil pin the same size as the forward assist pin which works awesome also......About the money spent on both when all tools are purchased......I know if you're building more then 2-3 AR uppers it's totally worth the money to do it yourself......Great video.....
Totally agree with Stanton. You are the consummate overachiever that makes me feel like a slacker. I dimpled (didn't use a jig- any guesses what happened? Lol). Great vid. Too late for me. I was able to straighten it out, but I'd go your route or NOT mess with the barrel. I Wonder how it affects the harmonics???
Not sure what the instructions say, but I'd want a good bit more interference than that. I think you reamed the hole a tiny bit too big. If you don't have it pinned pretty tight, there's not much advantage over a set screw block. Another excellent NSZ85 video! Easily the best AR build content on YT!
Built a few ARs, never pinned a gas block. The one I'm working on now is for the purpose of "SHTF" prepping. I want it to be a very reliable rifle. I bought a carbon fiber barrel to reduce heat if I need to throw out a high volume of rounds, however I also would like to pin the gas block. Is there a way I can assure that this jig would work to pin the gas block in my specific barrel? I'm unsure if pinning even works with carbon fiber, as not many people ever use them in videos.
So I’m about to do this and i have a question...after you reemed it and tapped the pin through,to me it looks like it went in way too easy.i thought I would need to tap it in and it have a much more tight fit,so it’s less likely to come out.you being able to just drop the pin in 3/4ths of the way seemed off.am I wrong? Or should it be exactly how you demonstrated?...thanks
Great video. Does the drill create a notch in the barrel? If you have an A2 front sight already can you just buy a low profile gas block designed to be pinned for an easier install?
Some people have commented on the necessity of not needing to pin a gas block. For most people, no it's not a "necessity". That's because most folks don't shoot their AR's much and many AR's are used for ranges, plinking, or hunting and not primarily for self-defense or hard life and death uses. When problems start happening with gas blocks is usually when a rifle gets ran hard. It gets HOT at the gas block and this causes a couple of problems. 1. Threadlocker is destroyed with enough heat. 2. With no threadlocker, the screws to work loose and the gas block to shift...and then you have a single shot rifle. Dimpling the barrel helps (delays significantly) but does not eliminate the problem. Real-world and hard-won experience with the M-series platform has shown that the taper pin method is extremely reliable. A good roll pin is also likely very reliable and I suppose that you could peen the threads on the set screws and that would help...but we KNOW that the taper pin method works. Which way you want to build/maintain your rifle/carbine is ultimately up to you but I know which I trust when my family's life is on the line.
That hand drill is walking all over the place and so are his tolerances and alignment/straightness. If you are going to do something like this you need to have and use a vertical mill or drill press. Otherwise he would have been far better simply dimpling the barrel for the set screws with a jig and staking the the set screws. No way is that going to come loose or walk off. Every mallninja claims otherwise though and have the scenario dreamed up in there heads. If you carelessly throw your weapon around or drop it, you probably won't live very long in a gunfight anyway. Get ran hard....like countless mag dumps? I try to end the fight with as few rounds as possible or a single fired very accurate, well placed shot. If you are in a situation where you are dumping magazine and after magazine you need to step up your game on your accuracy. You can't shoot for shit....obvious by that 1,500 round carbine course you have signed up for and taken. The winner in a gunfight is the first person who produces lethal hits. "Fast is fine, but accuracy is everything!" ~ Wyatt Earp
@John Doe That's an interesting position. While I think that people shouldn't purposefully drop kick their rifles, I have had to drag an M4/GAU-5 for work and crap happens. They get banged around, fall over, and get used as a landing crutch when people get prone in a hurry. People get sloppy when they are tired, hot, stressed, and sweating. I agree that he should use a drill press or at least a simple jig to keep his holes aligned and I did say that dimpling and staking, mostly staking, helps a lot. But the VAST majority of people, including many gunsmiths, think a little loctite is enough and don't peen (stake) their gas blocks. Once a rifle exceeds a slow firing pace this deficiency becomes apparent. As far as not running a rifle hard...that's a stupid comment that makes assumptions that I'm unwilling to abide by. First, nobody is talking about mag dumps, though that will certainly show deficiencies. I am personally unwilling to trust lives to a rifle that hasn't been thoroughly tested in circumstances that reasonably simulate a firefight even if that scenario is highly unlikely. And to bash people for taking good training classes is just willfully ignorant. If accuracy is king... fast repeatable practiced accuracy is imperial and the only way to get that is to get training and to practice. Your statements, other than about the tooling, are impractical and generally disproven by data collected by the FBI and military. Shootouts are rarely at long ranges outside of the military and they generally have a higher than seems reasonable round count. They certainly don't conform with your ideas of being some kind of stalwart six-shooting accuracy master while under stress...but I'm sure that you'll be the exception. Have a nice day. 🙂
@@derrick9653 Mallninjas beat the shit out of their weapons. Military and Law Enforcement doesn't. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-nMfq7vDZBd0.html
I’m not a gunsmith, let me get that out there. I asked Aero Precision if I needed to locktite their gas blocks screws and was told, no. Just torque them to 25 inch pounds and it would not move. So watching this video, I’m wondering if this is solving a problem that doesn’t exist.
Not a gunsmith either but I would have to agree. Seems like everyone from Leupold, Trijicon, Aero, Benelli, etc. People dealing with stuff fastened on high recoil type things, including very precision oriented devices like scopes. All say just use the proper torque and you're good to go. No need for Loctite or extra drilling etc. And to be honest, I'd rather have my 80 dollar FAT wrench, or a torque bar for the heavier things, and just check from time to time and make sure everything is tight. Preferable to drilling into my $600 barrel, or stripping Loctited screws in my RDS/Scope. Then either paying a gunsmith, or doing it myself, using a drill to other expensive parts of my gun like Leupold DPP or an equally expensive receiver.
@@lordofentropyWhich is why Trijicon attaches the TA51 mount to their ACOGs with red loctited screws from the factory, right? Because it’s “not necessary.” Seems pretty hypocritical of them
How much did you have to give for the gas block jig? I've been really wanting to pin some of mine but I'm scared to death I'll ruin my barrel, but with your video showcasing this jig makes me feel much more comfortable with the idea. Awesome video, any information would be greatly appreciated 👍
Thanks Nsz85. If I change a gas block to a low profile will I be able to pin it? It's pinned back the factory, but I'm not sure if the hole would be in the same spot. Any advise?
Nice video. Well done. So, what is the general consensus? Clearly the pin adds additional stability, but if dimple work is done well, and set screws are torqued to spec, is a pin really needed? Thanks.
Correct me if I'm wrong and I've heard this from accuracy gurus pinning hurts barrel harmonics which in turn hurts accuracy to some degree no? Same reason people go free float hardguard. If that's true doesn't doing this kinda go against the idea of an spr build? I wouldn't have pinned it. On a go to rifle for ITEOTWAWKI sure but not a paper puncher. Nice tutorial either way though. I liked the dimpling one. I thought doing that was more involved.
betatalk357 psshhhh iirc military m4s supplied by fn if I'm not mistaken... only need to be 3 moa capable at a 100 yards to pass quality. Not to mention chrome lining also affects accuracy. U won't find any high precision rifle with a non free float guard, chrome lined barrel and a pinned gas block if it's DI and not bolt action. Just because military m4s have doesn't mean it's just as accurate and unpinned. They're also chrome lined that's a big no no if you're aiming for sub moa accuracy which the military DOESNT on a m4
+John K depends which one you get. The MK12 was done quickly to fill a gap in the Arsenal. There is quite a bit of variation between different MK12s. You see the same thing right now in some of the M24s. You may have one that's all stock in 7.62x51 and another that The only original part is the receiver, in 300 WinMag. The last one I was issued was in .300 wm. It had a Mcmillan stock, had a new aftermarket barrel, and an after market scope replacing the Leopold.
+nemisans13 Doesn't harmonics have to do with repeatability? A pinned gas block wouldn't affect that. If you had a target crowned barrel then I guess I wouldn't pin a gas block. I really doubt it affects accuracy.
Question: I just ordered an upper that has a pinned low profile gas block DI system that I plan on swapping out for a low profile gas piston system. Manufacture says OK to swap out, but doesn't recommend pinning new gas block on barrel since barrel has already been pinned. Is it OK to pin a barrel twice from different gas blocks? Thank you
Always use a drill press ... When drilling metal always drill slow ... ream only after checking the pin fit ... This was over reamed, the set screws are doing all the work
Are you drilling just through the gas block or is it also going through outer part of the barrel? I know not through the bore cause that would be bad lol
Thanks. I contacted the company and they essentially said the same thing, that it isn't necessary. I have a pretty good view of the gas block through the hand guard. I can keep an eye if it starts to migrate.
+nsz85 it looked like it didnt take very much to tap the pin in. i just orderedmy jigs and everything and plan on doing this myself this week. i was wondering if the taper pin fit tightly enough.and if it help up for you
Colton Dunn I was thinking the same thing. Just don't go so big with the taper bit. And it will fit tighter. And it will take a lot more pressure taps to seat the pin.
I wonder how an end mill would work instead of the standard 118 drill bit. The jig wouldn't even be needed as it is used to prevent the bit from flexing after contacting the angled surface of the gas block. I would think after repeated use of the jig, the guiding hole would get egged out from the bit flexing slightly after contacting the gas block surface.
I've only purchased, not pinned my own barrels...that pin although technically pinned, was a bit loose I thaught. But there are no videos addressing any issues so I assume it's fine? 🤷
I shoot a bit but have never pinned any gas block what are the benefits to a pinned gas block I have a daniel defense mk12 barrel with a vltor clamp on low profile gas block
Do not attempt this with a nitride coated barrel, the coating is too hard for the drill and the reamer to cut. I had to use a solid carbide endmill to make a hole in mine and used 3/32 roll pin. Did it on a milling machine , no jig was necessary. I have 40 years experience in maching
Would this affect accuracy in any way? I'm using a wilson combat stainless barrel which regularly gets .5 MOA groups. I want the security of a pinned block, but I don't want to mess up that accuracy.
BigYeet, in your case consider just staking the set screws in place with a spring loaded punch. Probably the best of both worlds for you. Makes your block more secure without the variable of a pin.
I'm new at this, but wouldn't you pin the gas block OR dimple the gas block? With the dimples the only way for the block to twist or slide on the barrel would be if both screws loosened and backed out of the dimples. I don't see that happening if they have been loctited properly. Am I missing something?
You reamed the hole entirely to much, and now it's oversized. The pin is doing less than the set screws. Would not be surprised if it backed itself out.
Don't they sell gas blocks that uses the existing barrel notches that had A2 front sights? I see a lot of DIY to the stock blocks but haven't found any blocks that uses the existing notches. Just wondering?
so... you've tapped this barrel three times at the gas block Not even A1 or A2 front sight gas blocks with bayonet lugs have any taps locking them to the barrel.
+nsz85 I think what he means is -You' re going overkill on securing the gas block. He might be one of those $500 AR kinda guys. I like want your doing, keep up the great videos.
+Wong WayUSA oh no, not a $500 AR guy let me go tap, screw, pin, weld and glue needless shit. I need to secure my muzzle brake, let's harken back to the Brady Bill and pin that sucker on. Uh oh, that trigger guard could fall right off, let's tack weld that on! Why don't we get a solid piece of titanium to attach that pistol grip? you could be defending your life from Zombies and that pesky grip would fall right off! Oh shit, let's get a triple valvespring in the back of the buffer tube. Why not install a magazine buffer so it won't rattle? Hey, let's protect that muzzle crown by friction welding a mortar tube to it.
+NebulousCat They aren't the required for the gas block to be secure but there are a few reasons you may want to keep them there. 1) aesthetics 2) to prevent dirt from getting into those holes 3) to cover the exposed metal dimples and protect from corrosion 4)peace of mind that you have a pin and 2 dimples holding that sucker on there. haha
Why not just dimple the barrel and use a pointed set screw? As a machinist I would say you're running that drill much too fast for that material. Check out feeds and speeds for that size drill and that material.
