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Calico Jack
17 July 2015, 21:26
How often if at all do low profile gas blocks loosen? On the first rifle I built I used a 87industries pin block. I am not sure if I want to pin the gas block on the .300 blackout rifle I am building. This isn't a "battle rifle" or training rifle. Do any of you have a suggestion for c was .750 gas block I should use. It going under the rail so it doesn't have to look like the Fortis gas block. Thanks.

alamo5000
17 July 2015, 21:41
One or two times ago when I was shooting my gas block came completely loose. It blew forward about 3 or 4 inches which that is a huge case for pinning it. I have never pinned mine yet, but I am seriously considering it now.

As a temporary fix I put some loctite on the set screws and so far it's held up through more than 250 rounds so far. Fortunately my barrel came dimpled so (at least to me) that helps a whole lot. If it wasn't dimpled, that to me would cause a problem.

I don't think pinning is mandatory, but I am becoming more and more a believer in it. That said, so far loctite on the set screws has been doing well so far.

Please note though, I am a recreational shooter... many people here get to/need to shoot for work. If I was shooting for work as a LEO or anything... I wouldn't even bat an eye. EVERY gas block would be pinned.

VIPER 237
17 July 2015, 22:42
A properly dimpled barrel with vibratite or loctite is pretty damn secure, but pinning is IMO the most secure, however some feel that pinning the barrel can create stress on the bore and adversely affect performance.

JoshAston
18 July 2015, 08:34
The Mk12 Mod 1 uses an exposed set screw low profile gas block that's not pinned. So I'd say, no it's not necessary. I pin all of mine anyway

Hmac
18 July 2015, 09:20
Personally, I don't care what my "needs" are. I'm not a professional gun-handler, nor a professional carpenter, but I want to have utterly reliable firearms, and utterly reliable power tools, both for the same reasons. I would rather spend the extra bucks than just accept "probably good enough".

UWone77
18 July 2015, 09:32
Yes and No.

In my experience, it really depends on what you're using the gun for. If you're using the rifle as a tool for a living, then yes, I'd pin the gas block. All but 2 of my guns have pinned gas blocks. If this is just a range toy, and you don't want to put up with the expense or time to pin that gas block, you probably won't have any issues.

I've posted this picture before, but here's an example of dimpled barrel with loctite and set screws, shot suppressed:

http://i849.photobucket.com/albums/ab55/UWone77/IMG_0684_zps551614dc.jpg (http://s849.photobucket.com/user/UWone77/media/IMG_0684_zps551614dc.jpg.html)

GOST
18 July 2015, 09:38
All of mine are pinned due to a friends gas block coming loose, his still isn't pinned though.

MoxyDave
18 July 2015, 12:21
Loctite and similar threadlockers will melt instantly with the high temperatures at the gas block.

A ceramic adhesive such as Rocksett is much better suited for such high temperatures. I've never had one come loose, but I prefer pinned for anything but range toys. It's cheap insurance for something that might save a life.

alamo5000
18 July 2015, 12:39
On the same topic, about how much does it cost to pin a gas block? My regular guy doesn't do it so I need to find someone else.

tact
18 July 2015, 12:52
On the same topic, about how much does it cost to pin a gas block? My regular guy doesn't do it so I need to find someone else.

I sent mine to ADCO....I think it was 50$ per.

alamo5000
18 July 2015, 12:55
I sent mine to ADCO....I think it was 50$ per.

$50 plus shipping each way right? So maybe $75 bucks total?

Dstrbdmedic167
18 July 2015, 12:55
On the same topic, about how much does it cost to pin a gas block? My regular guy doesn't do it so I need to find someone else.

Rainier has 3 prices that I could find.

$29.95 for standard block, $44.95 for nitrited gas blocks and $74.95 for syrac Gen 2 gas block pinning.

alamo5000
18 July 2015, 13:10
Rainier has 3 prices that I could find.

$29.95 for standard block, $44.95 for nitrited gas blocks and $74.95 for syrac Gen 2 gas block pinning.

I wonder why the Syrac is more??? Maybe someone with gunsmith expertise can teach me something...

My current block is an SLR adjustable... I will try to find someone local that I can just take the upper to... I am thinking that will be easier than taking my rifle apart.

As for Rainier though, next time I buy a barrel I might get them to pin a block for me from the get go.

I didn't pin this one mainly because being my first rifle I didn't know about the ins and outs of it.

So yeah, when I first started vs right now I know a little more than when I started out...so the more I go the more I am thinking pinning might be a good idea...That said it adds cost and if I ever want to rebarrel my rifle it becomes a little less of an at home job, at least for that part. I also don't think a barrel nut will go over the gas blocks so you have to know what you are going to be using... (I could be wrong on the barrel nut thing so correct me if I am wrong).

UWone77
18 July 2015, 13:36
I wonder why the Syrac is more??? Maybe someone with gunsmith expertise can teach me something...

My current block is an SLR adjustable... I will try to find someone local that I can just take the upper to... I am thinking that will be easier than taking my rifle apart.

As for Rainier though, next time I buy a barrel I might get them to pin a block for me from the get go.

I didn't pin this one mainly because being my first rifle I didn't know about the ins and outs of it.

So yeah, when I first started vs right now I know a little more than when I started out...so the more I go the more I am thinking pinning might be a good idea...That said it adds cost and if I ever want to rebarrel my rifle it becomes a little less of an at home job, at least for that part. I also don't think a barrel nut will go over the gas blocks so you have to know what you are going to be using... (I could be wrong on the barrel nut thing so correct me if I am wrong).

I believe because it's melonite coated and requires a more expensive bit to drill.

I always get them pre-pinned from Rainier as well when I buy a new barrel as well as throwing on the barrel nut before the pin (if I know what handguard I'm using before hand) Makes putting everything together later that much easier.

tact
18 July 2015, 13:41
I wonder why the Syrac is more??? Maybe someone with gunsmith expertise can teach me something...

My current block is an SLR adjustable... I will try to find someone local that I can just take the upper to... I am thinking that will be easier than taking my rifle apart.

As for Rainier though, next time I buy a barrel I might get them to pin a block for me from the get go.

I didn't pin this one mainly because being my first rifle I didn't know about the ins and outs of it.

So yeah, when I first started vs right now I know a little more than when I started out...so the more I go the more I am thinking pinning might be a good idea...That said it adds cost and if I ever want to rebarrel my rifle it becomes a little less of an at home job, at least for that part. I also don't think a barrel nut will go over the gas blocks so you have to know what you are going to be using... (I could be wrong on the barrel nut thing so correct me if I am wrong).

The pinning on the gas block is not a pin and weld like on muzzle devices. It can be removed and put back in place fairly easy.

tact
18 July 2015, 13:46
$50 plus shipping each way right? So maybe $75 bucks total?

It's just 55$ per pin. Material of the GB doesn't affect price, as I've sent in just about every kind that you can think of.

alamo5000
18 July 2015, 14:14
OK that makes sense. Now I'm curious that if I want to remove the gas block after its pinned, how hard is it to take off? Is about like putting in or removing a gas tube pin or is it more involved than that?

JoshAston
18 July 2015, 14:19
You just hammer it out. If they used a taper pin it's directional, hit the small end. Some pins are really tight and by no means easy to remove, but they're still removable

Calico Jack
18 July 2015, 14:25
Thanks I just bite the bullet and buy another 87 industries pin block. They need to go on sale again damn it!

Hmac
18 July 2015, 14:39
I've had gas block pinned by some well-known gunsmiths. The guy that did the best job for me...pinned the block without outrageously scarfing up the barrel like the other places typically do was Dave Timm at Patrol Tactical. He did an excellent job pinning an 87 Industries block on a Voodoo nitrided barrel for me.

https://scontent-ord1-1.xx.fbcdn.net/hphotos-xaf1/v/t1.0-9/11214106_802320749822837_7929779326773880510_n.jpg ?oh=2c47f76a079f400b5d83e551c041c328&oe=5658BFB5

UWone77
18 July 2015, 14:42
Here's the last block Rainier did for me.


http://i1016.photobucket.com/albums/af282/richdkim77/IMG_3495_zpsgqzkwugo.jpg (http://s1016.photobucket.com/user/richdkim77/media/IMG_3495_zpsgqzkwugo.jpg.html)

alamo5000
18 July 2015, 21:20
Thanks for the pictures guys. Those pics are extremely helpful.

Ride4frnt
18 July 2015, 23:10
Just buy a noveske barrel with the gas block already drilled...it'll be fun they said...

Hmac
19 July 2015, 07:26
FWIW, I recall that Dave told me that the 87 Industries gas block works fine with the same jig that he uses for the BCM gas block.

MoxyDave
19 July 2015, 12:14
Just buy a noveske barrel with the gas block already drilled...it'll be fun they said...

Haha I've played that game before several times ... Their straight dowel pins are pretty dang tight aren't they? I found a little oil goes a long way ...

Ride4frnt
19 July 2015, 15:02
Haha I've played that game before several times ... Their straight dowel pins are pretty dang tight aren't they? I found a little oil goes a long way ...

You said it.

jbjh
20 July 2015, 09:46
I have zero experience with set screw gas blocks, but are people not drilling the dimples deep enough?


Sent from 80ms in the future
Much peace
Jimmy

alamo5000
20 July 2015, 11:33
I have zero experience with set screw gas blocks, but are people not drilling the dimples deep enough?


Sent from 80ms in the future
Much peace
Jimmy

The pressure is just too much, especially if you run the rifle hard. Suppressed is another issue.

Most of them hold fine but after a few hundred rounds the screws loosen up... If you loctite the set screw in place it helps to keep it from rattling loose.

gatordev
20 July 2015, 12:42
The pressure is just too much, especially if you run the rifle hard. Suppressed is another issue.

Most of them hold fine but after a few hundred rounds the screws loosen up... If you loctite the set screw in place it helps to keep it from rattling loose.

I have not had that experience. I completely get why people want to pin their gas blocks, but if it's a range gun, not pinning the gas block doesn't mean it's going to fall off. I have several rifles with over 2K rounds (many suppressed) and they've been fine. Also, as was mentioned earlier, Loctite is susceptible to heat, so Loctiting a high-heat source doesn't really guarantee anything. That's why Rockset will often be used on muzzle devices.

But again, if I had to rely on my weapon for more than recreational shooting, then I definitely understand the desire to pin.

Slippers
20 July 2015, 13:02
BCM doesn't pin their gas blocks. Never had an issue with any of mine, and I run a suppressor 100% of the time. Dimples, high temp permanent loctite, knurled-tip set screws and you'll be fine.

alamo5000
20 July 2015, 13:19
I have not had that experience. I completely get why people want to pin their gas blocks, but if it's a range gun, not pinning the gas block doesn't mean it's going to fall off. I have several rifles with over 2K rounds (many suppressed) and they've been fine. Also, as was mentioned earlier, Loctite is susceptible to heat, so Loctiting a high-heat source doesn't really guarantee anything. That's why Rockset will often be used on muzzle devices.

But again, if I had to rely on my weapon for more than recreational shooting, then I definitely understand the desire to pin.

I've obviously never pinned mine (yet) but when I recently swapped a gas block out I guess I forgot to put anything to lock the set screw in place. I went out shooting and didn't even get 100 rounds in and the set screw had worked loose and my gas block blew forward a few inches. It wasn't the end of the world and I was even able to fix it right there on the spot...but it did leave me thinking.

I'm not a professional shooter or anything myself but now that I'm kind of settled into what parts I like I think pinning might be an option if for nothing else I won't need to mess with it for the most part. That said when I got home that day I put some loctite on the set screws and a few hundred rounds since and its been holding up fine.

Pinning is a 100% sure method, but it doesn't mean it's the only thing that will work. Unlike me in my situation, I didn't do anything to secure the set screws and it nearly ended a range session before I could ever get started. That was on me as my bad, but in the end the lesson was to secure the gas block in one way or another so that it won't come loose.

gatordev
20 July 2015, 15:29
I've obviously never pinned mine (yet) but when I recently swapped a gas block out I guess I forgot to put anything to lock the set screw in place. I went out shooting and didn't even get 100 rounds in and the set screw had worked loose and my gas block blew forward a few inches. It wasn't the end of the world and I was even able to fix it right there on the spot...but it did leave me thinking.


I get that. All I'm saying is that it's not as definitive as you made it sound in your post. Dimpling can work, if done correctly. Fun fact: Not all gas blocks are truly what they say they are, as well. I've had a DD .750 gas block that I couldn't get on a barrel. Another gas block went on just fine (I honestly can't remember the make, but it was a mainstream manufacturer). So basic fit and finish can come into play, as well.

Another great option is a cut FSP or regular FSP. They're not going anywhere!

Aberration79
20 July 2015, 17:10
With as cheap as lo-pro gas blocks are, why not just stake the set screw?

alamo5000
20 July 2015, 18:39
All I'm saying is that it's not as definitive as you made it sound in your post.

Sorry about that. I never had the intention to make it sound like that.

alamo5000
20 July 2015, 18:40
With as cheap as lo-pro gas blocks are, why not just stake the set screw?

You know what? That sounds like it could work. Good thinking.

UWone77
20 July 2015, 19:09
With as cheap as lo-pro gas blocks are, why not just stake the set screw?

Meh.... I've seen some staking jobs on set screws. No Thanks.

SINNER
21 July 2015, 04:59
Here's the last block Rainier did for me.


http://i1016.photobucket.com/albums/af282/richdkim77/IMG_3495_zpsgqzkwugo.jpg (http://s1016.photobucket.com/user/richdkim77/media/IMG_3495_zpsgqzkwugo.jpg.html)

Very nice job.
I pin every block on every build now after having one walk forward on a properly dimpled barrel. I stopped doing the tapered pins about 5 years ago and switched to a roll pin. I have a .300 BO with over 5k rounds through it with only a roll pin (removed the set screws to see how the pin held and have never put them back) in the gas block. It has not budged even with a can shooting supers.

BoilerUp
21 July 2015, 06:56
Many of you know this, but I thought I'd point out that Ballistic Advantage (a WEVO sponsor) will pin a low-pro gas block at time of order of one of their barrels for $40, which includes the nitride gas block (basically, $30 for the block and $10 for pinning). I had this done on a barrel and was quite pleased with the results.

http://www.smugmug.com/photos/i-dDTgZFx/0/L/i-dDTgZFx-L.jpg

Aberration79
24 July 2015, 09:48
So what did you use to get the pin out and back in without beating the hell out of the gas block? I got 2 Noveske barrels. The first block I mutilated.

Ballistic Advantage
24 July 2015, 09:56
So what did you use to get the pin out and back in without beating the hell out of the gas block? I got 2 Noveske barrels. The first block I mutilated.

We use straight coil pins here at BA. Our armorer Clint made this video on how to install a gas block. He goes over the tips and tools needed for the install. You can use the same tools and tips to remove the gas block.

https://www.youtube.com/watch?v=IdqIVX-FGDk

Slippers
24 July 2015, 09:58
So what did you use to get the pin out and back in without beating the hell out of the gas block? I got 2 Noveske barrels. The first block I mutilated.

I've removed the pin a couple times on my Noveske barrel. I use a starret brand punch, appropriately sized, and tap it out. Barrel vice blocks make it easy so it won't rotate due to the off-centerline force.

Aberration79
24 July 2015, 10:32
We use straight coil pins here at BA. Our armorer Clint made this video on how to install a gas block. He goes over the tips and tools needed for the install. You can use the same tools and tips to remove the gas block.

https://www.youtube.com/watch?v=IdqIVX-FGDk

I am liking the sound of that. Have you ever done some torture testing?


I've removed the pin a couple times on my Noveske barrel. I use a starret brand punch, appropriately sized, and tap it out. Barrel vice blocks make it easy so it won't rotate due to the off-centerline force.

Yeah thats how I mangled the first one. Both of mine took some serious banging to get out, and getting the first one in wasn't too bad until that last bit. I didn't even bother with the second. I was hoping someone had a sweet jig but I have never found one.

The problem was it took so much that the barrel constantly rotated in a vice, and could never get a good enough block fashioned to come from above with it but straight. Being my first builds and one of the first things I got at it was pretty discouraging. No worries at least I can just get another block from Noveske when I want to do it right lol.

Slippers
24 July 2015, 10:43
You could always use a coiled roll pin instead of the solid one. Noveske used to use them awhile back. Makes it much easier to install/remove.

Calico Jack
24 July 2015, 14:04
We use straight coil pins here at BA. Our armorer Clint made this video on how to install a gas block. He goes over the tips and tools needed for the install. You can use the same tools and tips to remove the gas block.

https://www.youtube.com/watch?v=IdqIVX-FGDk

Is the gas block in the video the same one sold on your site? The block pictured doesn't appear to have to hole drilled for the roll pin under the barrel.

WHSmithIV
24 July 2015, 14:15
Meh.... I've seen some staking jobs on set screws. No Thanks.

Staking jobs on set screws would be bad juju. I think with proper dimpling of the barrel and just a very tiny drop of blue loctite on set screws then there is no need to pin the gas block. Is it better to pin the gas block? Maybe, but not necessarily so. I like to be able to remove them with a minimum of fuss. If you never intend to change a gas block you may as well go ahead and pin it in place or dimple the barrel for the set screws. If there is a possibility that you may want to change the gas block out to use an adjustable gas block or a piston system, I wouldn't do either until I found out what i really wanted for the rifle. Then I would dimple the barrel or even pin the gas block. The barrel will get shot out before the gas block would need changing I suspect. Then, it would be a case of changing the barrel and moving the gas block to the new barrel.

MoxyDave
24 July 2015, 14:57
DON'T USE LOCTITE ON GAS BLOCK SET SCREWS. Sorry to yell but some folks aren't listening. That shit melts at a pretty low temperature. Use Rocksett or another ceramic-based high-temperature adhesive. It's water-soluble and it's no harder to remove than Loctite, but it won't melt!

Slippers
24 July 2015, 15:22
Not contradicting anyone or saying what any of you do/recommend is right or wrong, but BCM uses high temp red loctite on their gas block set screws.

The thing about high temp permanent red is that even after it goes above the rated temp, it's still a real pain in the butt to remove.

UWone77
24 July 2015, 15:45
DON'T USE LOCTITE ON GAS BLOCK SET SCREWS. Sorry to yell but some folks aren't listening. That shit melts at a pretty low temperature. Use Rocksett or another ceramic-based high-temperature adhesive. It's water-soluble and it's no harder to remove than Loctite, but it won't melt!

Yup. Exactly Dave, why anyone would recommend blue loctite on a gas block is beyond me. As hot barrels get during fire, especially suppressed fire.

I only trust my AR's and life with pinned gas blocks or FSB's.

BoilerUp
24 July 2015, 20:35
Is the gas block in the video the same one sold on your site? The block pictured doesn't appear to have to hole drilled for the roll pin under the barrel.

The hole in the gas block gets drilled during the pinning process. I.e., you mount the gas block then drill one hole through both the block and the barrel.

WHSmithIV
24 July 2015, 20:47
Yup. Exactly Dave, why anyone would recommend blue loctite on a gas block is beyond me. As hot barrels get during fire, especially suppressed fire.

I only trust my AR's and life with pinned gas blocks or FSB's.

Can use the purple or even the red loctite - just a very tiny drop for the set screws. It all has to do with whether you think that there is a possibility after a couple hundred rounds that you will decide to change the gas block. How many thousands of rounds will get shot through the barrel before the barrel needs changing?...

As with everything with AR's, planned usage dictates how a rifle needs to be built for it to reliably perform it's intended function.

For me, it will take me probably around 10 years to put 5000 rounds through a barrel. I do have other rifles and I have shotguns. If a gas block will hold up for 5000 rounds, why would I spend extra to pin it?

UWone77
24 July 2015, 20:51
Can use the purple or even the red loctite - just a very tiny drop for the set screws. It all has to do with whether you think that there is a possibility after a couple hundred rounds that you will decide to change the gas block. How many thousands of rounds will get shot through the barrel before the barrel needs changing?...

As with everything with AR's, planned usage dictates how a rifle needs to be built for it to reliably perform it's intended function.

For me, it will take me probably around 10 years to put 5000 rounds through a barrel. If a gas block will hod up for 5000 rounds, why would I spend extra to pin it?

Will,

You plan to have 5k through one gun. I have 5k already though multiple guns. They all have FSB's or pinned gas blocks. You're right, usage dictates... but 5k rounds in 10 years is a very light shooting schedule, and frankly nowhere on the hard use radar. For you, yeah, you probably won't notice the difference as you average 41 rounds per month. For me, $30 to pin a gas block is money well spent.

Dstrbdmedic167
24 July 2015, 20:56
Yea I'm not even close to UW as far as shooting regularity but I shoot about 2-3 times a months an shoot a minimum of 2-300 rounds per session. Slippers can tell you I bring enough to appease us x3 for every gun I bring, which is usually all of them. (Thank God I haven't been pulled..) He does the same I might add.

$30 in a the scheme of things isn't much more than a box of ammo...

SINNER
25 July 2015, 04:10
It's not the vibrations from shooting that loosens the set screws but the expansion and contraction during the heat cycles. No thread locking compound can prevent that type of fastener stress from causing the block to shift.

Dave Timm
25 July 2015, 14:31
It seems the issue has already been addressed but obviously the pin is the most reliable. I personally pin all of mine and offer the service at the shop as Hmac mentioned. I've seen several gas blocks that were dimpled, even loctited, come loose at classes and matches. In addition to pinning, if customer requests we often use rocksett as well. Rocksett is easy to remove along with the pin if you ever need to remove the gas block or barrel nut. Also FWIW, I know some armorers that have used sleeving compound to seal and lock gas blocks. I can say that is very difficult to remove and requires significant heat. Melonite treated blocks and barrels are no issues to dimple or pin, just have to have the right bits.

Thanks for the compliment Hmac, always nice to hear that folks are happy with the work.

cjd3
9 August 2015, 23:52
My gas block just came loose (a little wiggle) after its second outing. I cleaned the threads, applied more Rocksett, and added more torque, I think 20"/#. We'll see how long that lasts. If it poops again, I'll replace it with an SLR adjustable, and get it pinned.