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Adjustable BCG vs Adjustable Gas Block

wastedtalent

Private
Minuteman
Jan 19, 2021
4
3
The Swamp
I have a Bootleg adjustable BCG and a Seekins adjustable gas block, and I'm trying to figure out which to use (or use both) on my AR pistol. It's an 11.5" DI system with a H buffer (but I also have an H2 and H3 to swap out, if necessary), and a YHM Turbo K lives on it. What setup would y'all recommend? I also would like to eventually put a PRI Gasbuster charging handle on it when they are back in stock. I'll take any other advice about the system, as well. Thanks in advance.
 
If the Turbo lives on it...

Set it in suppressed mode on the Bootleg and tune at the gas block for your optimum shooting conditions and ammo.

If you get grungy, or find yourself shooting lower power ammo, you can open up the Bootleg without digging around in your toolbox.

(In my experience, the Bootleg doesn't have enough adjustment to be able to run an optimal tune on both suppressed / and unsuppressed shorty. 11.5" carbine gas with high-back-pressure suppressor.)
 
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What are your thoughts on the gas buster?

I have two different guns set up with Bootleg carriers and Superlative gas blocks. Makes for a great system. Tune the block so that it cycles with the can off when the bcg is in "unsuppressed" mode, then switch it to "suppressed" when you put your can on.

A gas-limiting charging handle will be a big improvement when shooting suppressed. You can also do the RTV seal mod on whatever one you already have if you're looking to save money. Either work very well.
 
BCG or Adjustable Key is ALWAYS preferable to AGB.

There is not a AGB that has been invented yet that will not seize up and fail.
 
There is not a AGB that has been invented yet that will not seize up and fail.
This is generally true, although I've had unusually good luck un-seizing them lately.
If you buy $50-60 AGB's and consider them as consumables every time you swap out a smoked barrel the seizing issue doesn't matter that much.
 
As iktomi said the bootleg doesn't have a huge adjustment range. I like it because you can swap it out in 10sec if it has an issue. I use one in my 18in midlength gas Grendel and had to add a springco blue and an H3 buffer. Nice thing is it'll cycle 156g bullets at 1060fps if I swap in a carbine buffer.
 
the more I read on these the more I consider trying one on a 308 build. Any brand that is better than the rest?
 
BCG or Adjustable Key is ALWAYS preferable to AGB.

There is not a AGB that has been invented yet that will not seize up and fail.

Negative.

None of the adjustable bolt carriers I'm aware of have the adjustment range that is often necessary to tune an overgassed rifle to run correctly suppressed. Better than nothing, yes, but not as good as proper gas restriction. Also, proper gas restriction at the barrel port is functionally preferable to bleeding off excess in the receiver.

Quit worrying about whether the gas block seizes up; seizing up does not equal failure unless your goal is to click it back and forth rather than leaving it set. Get the adjustment set and leave it there. If it seizes, great, it's not going to lose adjustment. It'll continue to function exactly as it's supposed to - simulating a properly sized gas port.
Once that is done, an adjustable carrier like the Bootleg works great for switching between suppressed and unsuppressed. That's worked out very well for me, and I like the visibility of the Bootleg adjustment so I can tell at a glance what it's set to, no counting clicks or remembering what position it was in last time. This combination is definitely more expensive than spending $100-150 on a click-adjustable gas block, but it's also a lot more reliable.

To the OP - if you switch back and forth between suppressed and unsuppressed, use both. If it's suppressed all the time, just use the adjustable gas block. The Bootleg carrier on it's own likely won't bleed off enough gas; the adjustment range is more limited. Assuming you're talking about the $60 set & forget Seekins gas block - that's a good choice; simple and works well, if you set it up right the first time it won't give you problems.

If you have the newer switchable Seekins block (~$120 IIRC) I'd like to hear how it works for you.

A tip for setting a set and forget gas block: Run the small locking set screw in until it touches the adjustment screw, then remove the adjustment screw and turn the locking screw in another 1/8-1/4 turn. Now re-install the adjustment screw; it'll be an interference fit against the locking screw, making the adjustment take a bit of torque, and the little locking screw will never come loose. I've got a few that were set this way over 12 years ago and have never had one lose adjustment.
 
One other tip for the Bootleg carrier: if you have a Magpul grip, make yourself a little carrier adjustment tool with the grip plug. I just heated this hex wrench and pressed it into the plastic, no other bonding agent necessary, and it's secured well enough to hold up for the past few years with no signs of trouble.

I wish the carrier was adjustable by hand without a tool, but I don't think there is a better alternative on the market right now, so a tool that stays with the gun is my best solution.

WmecOw3h.jpg
 
How is that tool attached to the rifle, is that something you made?
 
How is that tool attached to the rifle, is that something you made?

The plastic part is just the standard Magpul grip plug that they ship with all of their grips. I made the steel part by heating and hammering, then grinding the end of a hex wrench flat. About as simple as you can get, really, maybe 10 minutes to complete.
 
Thanks, I see it now. At first blush, it looked attached to the 12 O'Clock rail.
 
Negative.

None of the adjustable bolt carriers I'm aware of have the adjustment range that is often necessary to tune an overgassed rifle to run correctly suppressed. Better than nothing, yes, but not as good as proper gas restriction. Also, proper gas restriction at the barrel port is functionally preferable to bleeding off excess in the receiver.

Quit worrying about whether the gas block seizes up; seizing up does not equal failure unless your goal is to click it back and forth rather than leaving it set. Get the adjustment set and leave it there. If it seizes, great, it's not going to lose adjustment. It'll continue to function exactly as it's supposed to - simulating a properly sized gas port.
Once that is done, an adjustable carrier like the Bootleg works great for switching between suppressed and unsuppressed. That's worked out very well for me, and I like the visibility of the Bootleg adjustment so I can tell at a glance what it's set to, no counting clicks or remembering what position it was in last time. This combination is definitely more expensive than spending $100-150 on a click-adjustable gas block, but it's also a lot more reliable.

To the OP - if you switch back and forth between suppressed and unsuppressed, use both. If it's suppressed all the time, just use the adjustable gas block. The Bootleg carrier on it's own likely won't bleed off enough gas; the adjustment range is more limited. Assuming you're talking about the $60 set & forget Seekins gas block - that's a good choice; simple and works well, if you set it up right the first time it won't give you problems.

If you have the newer switchable Seekins block (~$120 IIRC) I'd like to hear how it works for you.

A tip for setting a set and forget gas block: Run the small locking set screw in until it touches the adjustment screw, then remove the adjustment screw and turn the locking screw in another 1/8-1/4 turn. Now re-install the adjustment screw; it'll be an interference fit against the locking screw, making the adjustment take a bit of torque, and the little locking screw will never come loose. I've got a few that were set this way over 12 years ago and have never had one lose adjustment.

Its not a surgical device. Too many people who dont understand this platform or gun engineering in general end up with an unreliable weapon that once it gets a little fouling, is a paperweight.

You dont need to dial the gas down to the absolute minimum as you are destroying the saftey margin for a gun that needs to run dirty, in all enviroments, with a wide range of ammo,ect.

There is more than enough corse adjustment in both the bootleg and RCA key to tame a suppressed system to a point its not massivley overgassed while still being reliable.

Adjustable gas blocks by the very nature of how they work, fail and fail often. Its a high maintance item and the weak link in any DI gun that has one.

Fix the gas port or use a restricted gas tube if you want to fine tune the systen more than the carrier affords.

An AR is a complicated system of ballace and if you dick with one thing ( spring rate, buffer,ect) you have to account for it somewhere else.

The absolute number one priority for any gun is reliability. Everything else is secondary.

Colt , LMT, KAC, DD BCM may know a bit more than you about how to build a gas system.
 
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Its not a surgical device. Too many people who dont understand this platform or gun engineering in general end up with an unreliable weapon that once it gets a little fouling, is a paperweight.

You dont need to dial the gas down to the absolute minimum as you are destroying the saftey margin for a gun that needs to run dirty, in all enviroments, with a wide range of ammo,ect.

There is more than enough corse adjustment in both the bootleg and RCA key to tame a suppressed system to a point its not massivley overgassed while still being reliable.

Adjustable gas blocks by the very nature of how they work, fail and fail often. Its a high maintance item and the weak link in any DI gun that has one.

Fix the gas port or use a restricted gas tube if you want to fine tune the systen more than the carrier affords.

An AR is a complicated system of ballace and if you dick with one thing ( spring rate, buffer,ect) you have to account for it somewhere else.

The absolute number one priority for any gun is reliability. Everything else is secondary.

Colt , LMT, KAC, DD BCM may know a bit more than you about how to build a gas system.
Your arguments are crap. Half of that is ranting against something nobody said. The other half shows a clear lack of actual experience. See the Bootleg carrier in my pic above? Full open in position 4 was still over gassed on several rifles with suppressors added. That’s just one example.

“Fix the gas port” huh. Yeah let’s go re-drill that to a smaller size. What the heck do you think an adjustable gas block does, if not to fix an oversized gas port? Your assertion that an adjustable tube is somehow better is absurd, and the claim that a set and forget gas block requires maintenance is equally foolish.

I think you don’t really have any idea about this stuff and just bought in to the mantra that adjustable gas blocks are bad. Go eat your crayons somewhere else.

Edit - I remembered who you are and that you have a history of saying and arguing half-truths and absurdities here, so that’s on me for getting sucked into your stupidity. I’ll bow out now, and just hope the OP doesn’t get led too far astray by your posts.
 
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Child please. I was building and fixing small arms for the .mil before you probally ever touched a gun.

If you dont understand how a non moving part is preferable to a mechanical one with a high failure rate, then you clearly dont know as much as you think.

Look at all of the high vollume DI guns used by the military that use adjustable blocks especailly by those running cans.......look at the m4s with agbs...look at the mk18, mk11, mk12, Sopmod block 2, URGI , sr16 , lmt or any issued DI gun/upper.....there are just so many of them. That is what we call a hint.

Go grab yourself a snickers.
 
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Oh, look. @CrabsandFootball & I agree on something. Mostly, anyway ;)

Adjustable gas anything is fiddly & prone to failure. Gas blocks, BCGs, & triggers all included.

Grab one of these

One of these

Run your H2

Sell your adjustable gas blog & bolt carrier & back order the Lantac Enhanced bcg in whatever finish makes you happy (I have the TiN because it doesn't stain like NIB-X).

That's what I'd do, anyway. YMMV
 
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Its been explained many times, and if you had the experience you would know this.

Generally they seize up. The leaf or valve that provides tension in the current setting will get locked up leaving that setting as the only one. Or the small detents, springs or sheet metal inside will fail. Many use a much softer alloy with inferior heat treating compared to a CMV barrel so you also get erosion that eats away at the parts causing gas creep. Most are just poorly designed and some are better than others, but even the "good" ones will fail under hard use.

Now combine that with generally being under a hanguard and you have a depot level action that is required to fix it.

That is just ONE of the reasons why a carrier or carrier key is preferable. Not only are they inherently more reliable, but should they sieze up you can fix it in the field in about 2 minutes.

And even them I would ONLY run an adjustable carrier on a working gun if I had to run suppressed. You are taking on additional risk and have to be aware of that. There is a reliability tradeoff for shootability.
 
What are your thoughts on the gas buster?

They're certainly better than nothing.

I don't use adjustable gas blocks, something to fail, something to fuck with. The switchblock on Noveske is okay, so is the factory FN shit on the Mk rifles.

Just use the appropriate buffer and call it a day.

FWIW, military rifles are overgassed on purpose so they'll remain reliable under diverse conditions. I tend not to fuck with that too much.
 
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Clearly thats a deal breaker for someone that fiddles with their adj everytime they shoot their rifle. 🤷‍♂️
I guess?
Except if you fiddled with it all the time it wouldn't seize up.

Weakest link... something about square ranges...
blah blah... failure...
I was an armorer while you where in diapers!
 
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I've never seen a current gen SLR, Superlative, or Seekens (the detent one) adjustable gas block fail. I've seen a lot and run them a lot. They simply do not fail. Technically I'm sure you are inducing some minuscule amount of increased chance to fail....but you do the same thing with an adjustable stock, optics, and so on and those are all GTG now. Just took some time and some tech refining to get there. We are there with adjustable gas blocks now, period.

Yes, SOME will seize up if you don't drop some lube in and move them every 500-1000 rounds or so. But even then they still work just as well as your small gas port or a regular block would. And they are pretty easy to unseize in most cases if you were too lazy to do the preventative route.

Anyone saying otherwise simply has an axe to grind and lives in a non-fact based world.

I will say one annoying as fuck thing is all the cheap knock off adjustable gas blocks out there that do actually suck and will fall apart....
 
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Why won't anyone define "failure" of an AGB?
Because logic escapes some people.

The argument seems to be that moving parts are bad. But if a gas block adjustment seizes up so it doesn't adjust, that's a failure. Did I get that right?

Personally I adjust my gas blocks when I first set up the rifle, and then pretty much never touch them again. If they're seized up, great, that's even better. Nothing fails when that happens, and the function is exactly the same as if the gas port were perfectly sized for my loads and my setup. But apparently that's fiddly and bad for reliability, or so we're told.

But somehow adjustable gas keys and adjustable gas tubes are better? Keeping in mind that an adjustable gas key means a set screw in a moving part (the carrier) usually without any locking screw. But somehow that's more reliable and I think we're supposed to believe that the military uses them too? Seems like this logic is more of a maze than a straight line.
 
Personally speaking, I have used them in the past, while I have never really had any issues, I am just not a fan of the concept in general considering where the weapon system is at today.

I think that adjustable gas blocks were developed as a result of getting late 90's early 2000 silencers, to run reliably on AR's in the civilian market. and to a certain extent, I believe they do achieved this. How effective or reliable are these items can be debated, but for 99 percent of shooters I really don't think it really matters, they are not going to get anybody killed in the street

With that being said, in the past 5 years, silencers have come a long way, and the development of low pressure cans makes soo much more sense to me and just lead to a more pleasant shooting rifle, that is less susceptible to ammo or environmental changes. I am making a sacrifice in DB's but considering the nature of 556 gas guns, I am ok with this.

If I only had one can and it could be considered higher pressure, I think that something like an adjustable gas block or a BRT gas tube make great sense, but since I do have a low pressure can that I really like, I honestly am good to go.
 
I am just not a fan of the concept in general considering where the weapon system is at today.

I think that adjustable gas blocks were developed as a result of getting late 90's early 2000 silencers, to run reliably on AR's in the civilian market.

That doesn’t accurately reflect the reality of gas bocks on a modern AR. Adjustable gas blocks are used more than ever these days as more people understand the advantages of a properly tuned rifle, and as suppressors become more common. They are definitely not a hold over from earlier days as you imply.

The reason they’re being used is a direct result of most barrels being over gassed from the factory, which itself is a result of the wide variety of ammo in use and manufacturers wanting to avoid paying for barrel returns. That part makes sense for the manufacturers; you get a lot more happy customers if your barrels are a bit over gassed than if they only run on good ammo. You kind of have to understand probability distributions to really get into this, but the point is that most barrels are set up to work with the largest variation of ammo and rifles possible. That means some people end up with setups that are just right, and a few are even under gassed still, but most of us end up with overgassed barrels. (Of course there are exceptions, we can all agree on that)

Adding a suppressor to an over gassed barrel makes it even more over gassed. Guys are talking here about not wanting a system that’s barely on the edge of functioning, but how many realize how close their rifle is to that line on the other end (too far over gassed) with a suppressor on it? I don’t remember how many times I’ve looked at brass from rifles used this way and seen major signs of early unlocking, including rims being ripped partly off. A setup like that is just a question of when, not if, it will fail.

And yeah, there’s a lot of improvement in newer suppressors designed for semi auto rifles, and that’s a great thing. But even the best of them still makes a big difference between suppressed and unsuppressed and can benefit from proper gas tuning.

None of the comments or concerns about click adjustments, springs, or leaves have anything to do with the OP’s question though. That’s not the kind of gas block he has, if I understand what he’s got. That Seekins block has just a simple set screw partially blocking the hole; there’s not much to go wrong if it’s set up correctly from the start. That type of gas block isn’t for everyone, but if they fail it’s pretty much always user error. Just set it and leave it alone; no fiddling, no maintenance.
 
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Also, don’t waste your time with pigtail gas tubes. They’re a gimmick that do nothing for gas tuning. Some people claim they increase dwell time, but they do not. Dwell time is a function of the distance between the gas port and the muzzle (as well as bullet velocity across that distance), and lengthening the gas tube does nothing to change that.
 
That’s not true at all. Adjustable gas blocks are used more than ever these days as more people understand the advantages of a properly tuned rifle.

The reason they’re being used is a direct result of most barrels being over gassed from the factory, which itself is a result of the wide variety of ammo in use and manufacturers wanting to avoid paying for barrel returns. That part makes sense for the manufacturers; you get a lot more happy customers if your barrels are a bit over gassed than if they only run on good ammo. You kind of have to understand probability distributions to really get into this, but the point is that most barrels are set up to work with the largest variation of ammo and rifles possible. That means some people end up with setups that are just right, and a few are even under gassed still, but most of us end up with overgassed barrels. (Of course there are exceptions, we can all agree on that)

None of the comments or concerns about click adjustments, springs, or leaves have anything to do with the OP’s question though. That’s not the kind of gas block he has, if I understand what he’s got. That Seekins block has just a simple set screw partially blocking the hole; there’s not much to go wrong if it’s set up correctly from the start. That type of gas block isn’t for everyone, but if they fail it’s pretty much always user error. Just set it and leave it alone; no fiddling, no maintenance.
I can't disagree with any of this, only that if one avoids high pressure cans, none of this stuff is really needed. Just use the right tool for the job.

We have put millions upon millions of rounds down range and know what works and what doesn't work. I just don't think that we need to reinvent the wheel.

Thats not to say there is not a place in the market for say something like a JP15.
 
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That doesn’t accurately reflect the reality of gas bocks on a modern AR. Adjustable gas blocks are used more than ever these days as more people understand the advantages of a properly tuned rifle, and as suppressors become more common. They are definitely not a hold over from earlier days as you imply.

The reason they’re being used is a direct result of most barrels being over gassed from the factory, which itself is a result of the wide variety of ammo in use and manufacturers wanting to avoid paying for barrel returns. That part makes sense for the manufacturers; you get a lot more happy customers if your barrels are a bit over gassed than if they only run on good ammo. You kind of have to understand probability distributions to really get into this, but the point is that most barrels are set up to work with the largest variation of ammo and rifles possible. That means some people end up with setups that are just right, and a few are even under gassed still, but most of us end up with overgassed barrels. (Of course there are exceptions, we can all agree on that)

Adding a suppressor to an over gassed barrel makes it even more over gassed. Guys are talking here about not wanting a system that’s barely on the edge of functioning, but how many realize how close their rifle is to that line on the other end (too far over gassed) with a suppressor on it? I don’t remember how many times I’ve looked at brass from rifles used this way and seen major signs of early unlocking, including rims being ripped partly off. A setup like that is just a question of when, not if, it will fail.

And yeah, there’s a lot of improvement in newer suppressors designed for semi auto rifles, and that’s a great thing. But even the best of them still makes a big difference between suppressed and unsuppressed and can benefit from proper gas tuning.

None of the comments or concerns about click adjustments, springs, or leaves have anything to do with the OP’s question though. That’s not the kind of gas block he has, if I understand what he’s got. That Seekins block has just a simple set screw partially blocking the hole; there’s not much to go wrong if it’s set up correctly from the start. That type of gas block isn’t for everyone, but if they fail it’s pretty much always user error. Just set it and leave it alone; no fiddling, no maintenance.
You hit the nail on the head. I began to see signs of over gassing - resulting in a failure to extract. I do plan on running both the seekins AGB and the Bootleg, I believe, and if it seizes, so be it. I have contingency plans for all of my systems - replacement parts, etc. The goal is still reliability, so I'm not going for that competition feel where the weapon won't cycle if you have a heavy fart while operating. Furthermore, I enjoy maintaining and fine tuning my set ups, so the only true loss is ammo.
 
While Im not going to get into the what is better argument here... I will say Ive used LOTS of all the AGB on the market. JP, Seekins, SLR, POF, SLA, etc... I have "seized" ALL of them but I shoot a lot of rounds. I have only had 1 fail completely where the gun stopped properly feeding after working great for many thousands of rounds.. Replacing the gas block fixed the issue.

For those of you that put an AGB on a precision AR, etc. and shoot it for the life of the barrel and dont touch settings after getting it tuned properly, its fine. But someone like me that is constantly changing barrels for different testing and reviews, they have been a frustrating part with seizing....

I have been testing the Rubber City Adjustable gas key carriers for 6+ months now on a 20" precision AR, a custom 22" Krieger 308 AR and a new 14.5" 300 HamR AR. I am a huge believer of these things. They are SO much easier to adjust, no seizing and takes 2 seconds. No worrying about seizing, or your handguard being in the way of the adjust screw on some AGB (looking at you JP).

The argument that you cant tune gas as well with an adjustable gas key on carrier vs an adjustable gas block is bogus.. At least with the RCA.. Ive tested this side by side using the RCA adjustable carrier vs a Superlative Arms. Tuned exactly like the AGB.. Screw the adjustment screw all the way down (gas turned off) open 1 full turn, then shoot 1 round and turn 1/4 turn till your feeding rounds reliably.. Now shoot 50rd to confirm gas, most of the time you open another 1/4 to 1/2 turn.

Another thing, I have seen guys with 2 BCG's as well... 1 for suppressed and 1 for unsuppressed...both tuned for said use. Just another option... RCA also sells adjustable gas keys for you to install on your existing BCG as well. Im very happy with mine to date and I have a LOT of rounds on 2 of them.
 
I can't disagree with any of this, only that if one avoids high pressure cans, none of this stuff is really needed. Just use the right tool for the job.
While the OP was asking about suppressed use, all my AGB experience is unsuppresed and I can absolutely say with certainty that there are significant performance gains to be had by properly tuning gas. Not the "my butt dyno says I gained 10hp" gains, but actual measured improvements.
Adding reciprocating mass or spring rate to compensate for excessive gas is a bass ackwards way of fixing the symptoms, not the problem.
 
While Im not going to get into the what is better argument here... I will say Ive used LOTS of all the AGB on the market. JP, Seekins, SLR, POF, SLA, etc... I have "seized" ALL of them but I shoot a lot of rounds. I have only had 1 fail completely where the gun stopped properly feeding after working great for many thousands of rounds.. Replacing the gas block fixed the issue.

For those of you that put an AGB on a precision AR, etc. and shoot it for the life of the barrel and dont touch settings after getting it tuned properly, its fine. But someone like me that is constantly changing barrels for different testing and reviews, they have been a frustrating part with seizing....

I have been testing the Rubber City Adjustable gas key carriers for 6+ months now on a 20" precision AR, a custom 22" Krieger 308 AR and a new 14.5" 300 HamR AR. I am a huge believer of these things. They are SO much easier to adjust, no seizing and takes 2 seconds. No worrying about seizing, or your handguard being in the way of the adjust screw on some AGB (looking at you JP).

The argument that you cant tune gas as well with an adjustable gas key on carrier vs an adjustable gas block is bogus.. At least with the RCA.. Ive tested this side by side using the RCA adjustable carrier vs a Superlative Arms. Tuned exactly like the AGB.. Screw the adjustment screw all the way down (gas turned off) open 1 full turn, then shoot 1 round and turn 1/4 turn till your feeding rounds reliably.. Now shoot 50rd to confirm gas, most of the time you open another 1/4 to 1/2 turn.

Another thing, I have seen guys with 2 BCG's as well... 1 for suppressed and 1 for unsuppressed...both tuned for said use. Just another option... RCA also sells adjustable gas keys for you to install on your existing BCG as well. Im very happy with mine to date and I have a LOT of rounds on 2 of them.

You’re talking about serviceability. I’m talking about reliability. Two completely different things.

Your gas block might not be serviceable over the life of the barrel, but it CAN be reliable.

Switching between suppressed and unsuppressed is a serviceability thing that a lot of people try to solve with constant gas block adjustment, but the OP’s Bootleg carrier handles that better anyway and eliminates the need for a serviceable gas block.
 
You’re talking about serviceability. I’m talking about reliability. Two completely different things.

Your gas block might not be serviceable over the life of the barrel, but it CAN be reliable.

Switching between suppressed and unsuppressed is a serviceability thing that a lot of people try to solve with constant gas block adjustment, but the OP’s Bootleg carrier handles that better anyway and eliminates the need for a serviceable gas block.

You must be talking to someone else because I never talked about reliability or serviceability anywhere in my post so dont put words in my mouth. I stated facts and personal experiences with BOTH options after 100,000's of rounds over many years using them. Period. Dont drag me into your guys cat fight
 
You must be talking to someone else because I never talked about reliability or serviceability anywhere in my post so dont put words in my mouth. I stated facts and personal experiences with BOTH options after 100,000's of rounds over many years using them. Period. Dont drag me into your guys cat fight

I think you misunderstand me. When you are talking about the ability to change gas block settings for switching to different barrels, you’re looking for serviceability.

When I’m looking for a gas block to stay adjusted over the life of a barrel, I’m looking for reliability.

None of that counters your facts and experience. It just points out that your goal is different than many others, which you also pointed out.
 
For those of you that put an AGB on a precision AR, etc. and shoot it for the life of the barrel and dont touch settings after getting it tuned properly, its fine. But someone like me that is constantly changing barrels for different testing and reviews, they have been a frustrating part with seizing....

Particularly this part right here. You have a different goal than me; I’m in that first group.
 
I have only had 1 fail completely where the gun stopped properly feeding after working great for many thousands of rounds..

Youre picking parts of my reply that you want to zero in on. Here is another regarding "reliability" if you want to talk about both.. AND ill let the forum member chime in if he so wishes about his 6.5cm upper he sent me recently that he bought new that stopped feeding rounds. Was under gassed and not feeding rounds. The AGB failed and was no longer passing enough gas to properly cycle the BCG and pick up rounds... No matter how the adjust screw was adjusted, full wide open it still wouldnt work.. Check gas tube with air hose, no blockage, checked barrel gas port, no blockage... Replaced AGB (ill leave the name out as not to bash anyone but its one of the big names being discussed here) and his problem was gone. Back to feeding rounds.

So, my post above said essentially they work, but they also can fail. Not serviecability fail, but reliability fail as well. Those are facts. Does it happen every day? No. Can it happen, yes. My sneaky bag AR that goes anywhere I go and my house AR's that I would bet my life on all have Geissele fixed gas blocks. My precision AR's/range toys all have some form of adjustable gas block or BCG on them...

Take that info and do what you want with it.
 
While Im not going to get into the what is better argument here... I will say Ive used LOTS of all the AGB on the market. JP, Seekins, SLR, POF, SLA, etc... I have "seized" ALL of them but I shoot a lot of rounds. I have only had 1 fail completely where the gun stopped properly feeding after working great for many thousands of rounds.. Replacing the gas block fixed the issue.

For those of you that put an AGB on a precision AR, etc. and shoot it for the life of the barrel and dont touch settings after getting it tuned properly, its fine. But someone like me that is constantly changing barrels for different testing and reviews, they have been a frustrating part with seizing....

I have been testing the Rubber City Adjustable gas key carriers for 6+ months now on a 20" precision AR, a custom 22" Krieger 308 AR and a new 14.5" 300 HamR AR. I am a huge believer of these things. They are SO much easier to adjust, no seizing and takes 2 seconds. No worrying about seizing, or your handguard being in the way of the adjust screw on some AGB (looking at you JP).

The argument that you cant tune gas as well with an adjustable gas key on carrier vs an adjustable gas block is bogus.. At least with the RCA.. Ive tested this side by side using the RCA adjustable carrier vs a Superlative Arms. Tuned exactly like the AGB.. Screw the adjustment screw all the way down (gas turned off) open 1 full turn, then shoot 1 round and turn 1/4 turn till your feeding rounds reliably.. Now shoot 50rd to confirm gas, most of the time you open another 1/4 to 1/2 turn.

Another thing, I have seen guys with 2 BCG's as well... 1 for suppressed and 1 for unsuppressed...both tuned for said use. Just another option... RCA also sells adjustable gas keys for you to install on your existing BCG as well. Im very happy with mine to date and I have a LOT of rounds on 2 of them.
Now you have made me second guess the purchase of my superlative agb. The rubber city key is 50 bucks vs 90 for the agb and a more elegant solution, and if the key works better....doh!!! But on the plus side since I shoot once every never the agb should be gtg....sob...
 
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Youre picking parts of my reply that you want to zero in on. Here is another regarding "reliability" if you want to talk about both.. AND ill let the forum member chime in if he so wishes about his 6.5cm upper he sent me recently that he bought new that stopped feeding rounds. Was under gassed and not feeding rounds. The AGB failed and was no longer passing enough gas to properly cycle the BCG and pick up rounds... No matter how the adjust screw was adjusted, full wide open it still wouldnt work.. Check gas tube with air hose, no blockage, checked barrel gas port, no blockage... Replaced AGB (ill leave the name out as not to bash anyone but its one of the big names being discussed here) and his problem was gone. Back to feeding rounds.

So, my post above said essentially they work, but they also can fail. Not serviecability fail, but reliability fail as well. Those are facts. Does it happen every day? No. Can it happen, yes. My sneaky bag AR that goes anywhere I go and my house AR's that I would bet my life on all have Geissele fixed gas blocks. My precision AR's/range toys all have some form of adjustable gas block or BCG on them...

Take that info and do what you want with it.
I have no disagreement with anything you’ve said in this thread. It sounds like you’re seeing an argument when there isn’t any.
 
So to summarize, when an AGB fails it ends up acting just like a non adjustable block. Which is catastrophic, so just get a non adjustable block. Got it.
Did you read what was wrote? You are missing over half of the post, which includes a gun that stops working.

There seems to be a massive issue here where people cannot comprehend what is posted or they just latch on to a piece of it instead of reading it totality.

I don't understand how you can type something plain and clear and people still cannot grasp the concept.
 
I've never seen a current gen SLR, Superlative, or Seekens (the detent one) adjustable gas block fail. I've seen a lot and run them a lot. They simply do not fail. Technically I'm sure you are inducing some minuscule amount of increased chance to fail....but you do the same thing with an adjustable stock, optics, and so on and those are all GTG now. Just took some time and some tech refining to get there. We are there with adjustable gas blocks now, period.

Yes, SOME will seize up if you don't drop some lube in and move them every 500-1000 rounds or so. But even then they still work just as well as your small gas port or a regular block would. And they are pretty easy to unseize in most cases if you were too lazy to do the preventative route.

Anyone saying otherwise simply has an axe to grind and lives in a non-fact based world.

I will say one annoying as fuck thing is all the cheap knock off adjustable gas blocks out there that do actually suck and will fall apart....
You never seeing it is indicative of low experience level and does not represent actual real world results.

I have never seen " XXXXXXXXXX " so it must not be true.

They have all been tested and run hard and do not hold up.

If they were reliable you would see them on hard use, duty guns. Being able to take a standardized system and add a gas block so you can run a wide a wide variety of ammo and suppressors is a no brainer. Except for the fact its a liability more than a benefit.

Colt, Diemeco, LMT, BCM, KAC, DD, Gieselle...........All of the top DI manufactures in the world who comprise of 95% of hard use guns.........and they don't offer any guns with adjustable gas blocks.

Its always comical when the novices want to argue with SMEs. No wonder soo many get run off. Not worth arguing with the ignorant.
 
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Looks like many reputable members have chimed in.
Some interesting differing opinions too.
So what are you thinking OP?
 
Did you read what was wrote? You are missing over half of the post, which includes a gun that stops working.

There seems to be a massive issue here where people cannot comprehend what is posted or they just latch on to a piece of it instead of reading it totality.

I don't understand how you can type something plain and clear and people still cannot grasp the concept.
Went back and read it again. You said they seize up, which I generally agree with. It's happened to me many times. The great thing is it becomes a non adjustable block at that point and nothing bad happens. Then you said something about garbage aluminum blocks eroding to the point of malfunction, which I've also seen and agree with, but is an entirely separate issue that has nothing to do with the block being adjustable. In fact the only aluminum blocks I see still around are non adjustable.

Duty rifles don't use them because tards be everywhere. These tards can't help but turn any screws they see without having a clue what they're doing. If tards in uniform did this it could be real bad. When the tards dumping mags at the local indoor range dick with adjustments they don't understand no one gets hurt.
 
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Went back and read it again. You said they seize up, which I generally agree with. It's happened to me many times. The great thing is it becomes a non adjustable block at that point and nothing bad happens. Then you said something about garbage aluminum blocks eroding to the point of malfunction, which I've also seen and agree with, but is an entirely separate issue that has nothing to do with the block being adjustable. In fact the only aluminum blocks I see still around are non adjustable.

Duty rifles don't use them because tards be everywhere. These tards can't help but turn any screws they see without having a clue what they're doing. If tards in uniform did this it could be real bad. When the tards dumping mags at the local indoor range dick with adjustments they don't understand no one gets hurt.

Just when you think someone can't say anything dumber.....

You literately cannot fucking read and put 2 simple concepts together.

SOCOM, HRT, JSOC and every elite tactical unit in the world is all tards right? They can be trusted with millions of dollars of the most cutting edge equipment and technology but can't handle an adjustable gas block.

You should really stop posting or calling ANYONE a tard.
 
One other tip for the Bootleg carrier: if you have a Magpul grip, make yourself a little carrier adjustment tool with the grip plug. I just heated this hex wrench and pressed it into the plastic, no other bonding agent necessary, and it's secured well enough to hold up for the past few years with no signs of trouble.

I wish the carrier was adjustable by hand without a tool, but I don't think there is a better alternative on the market right now, so a tool that stays with the gun is my best solution.

WmecOw3h.jpg

I have the Rubber City and the 2A Armament adjustable BCGs. The Rubber City is functional but a pain to adjust when you have to remove it each time.

The 2A is a joy. I prefer it to the Bootleg since it has a wider range of adjustment: https://www.2a-arms.com/category-s/200.htm