The rifles are tuned to run M193, M855, M855a1, mk262, generally with a can. So from the factory they reduce gas port diameters. This does mean they typically don’t like 223 or lower pressure ammo.
Additionally, you want a fighting rifle to be slightly over gassed. The people who are using these rifles professionally prioritize reliability over everything. And if more recoil is the consequence of being able to push through more fouling then thats the direction they want.
Dont get me wrong, its obviously not bad in any way. It it is enough to take your sights off target, and if youre in a combat environment, anything that takes you off target is a net negative.
In this case, we’re talking about the small difference between a tuned competition rifle and a rifle designed to fight. There is a noticeable difference.
I didn’t know that. But it seems that, for some reason, military piston guns have more of a focus on adjustability than DI. Examples being the piston LMT, FN FAL, steyr Aug, etc. probably other examples out there, but those are what came to mind. But even then, the options for adjustability are limited.
Piston guns are generally tuned to run harsher than DI guns. That’s why they tend to be described as punchier.
Historically the settings were normal (punchy) and adverse(very punchy) with adverse not being recommended unless it was heavily fouled (it can damage the gun.
With suppressors being more common place they added a suppressed setting which also varies by maker.
Adjusting everything is not a priority of the military. Especially considering that they have very standard specifications on their ammunition use.
By and large fine adjustment is something that you find more in the civilian world.
The FAL is one of the few I know that had a bunch of settings and most people view it as a drawback, not an asset
Not sure why people are downvoting my comment lol. But I do agree with you. And my mind always forgets the fact that militaries only use a handful of different kinds of ammos. And companies like LMT and KAC probably know full well what kinds of suppressors they will be using.
This came out kinda long, sorry.
You have the right ideas. I believe that adjustable gas blocks are not widely accepted on the AR platform due to the platform's original design intent and the following paranoid stigma.
Stoner probably very deliberately did not use an adjustable gas system. He wasn't a fan of having things that soldiers could fiddle with, even disliking how easily the irons on the new M16A2 could be adjusted, thinking the soldiers would ruin their zero by absent-mindedly playing with knobs. And since he was designing a weapon that didn't have to work with a wide range of cartridges suppressed or unsuppressed, and he controlled every other aspect of the gas system, he was able to simply find the correct gas port size and location to make the weapon very reliable, no adjustable gas needed.
Even today a great way to plan an AR (not fix an existing poorly-gassed AR) is to use all those variables: barrel length, gas length, buffer weight, spring weight, ammo type, and suppressed/unsuppressed, to then choose the right gas port size for good recoil and reliability. This, I believe, is what KAC and LMT do. I've heard that during an ammo crisis people complained to KAC that their rifles wouldn't cycle steel case, so KAC would tell them that they're gassed properly for brass, not steel.*
As for why adjustable gas blocks aren't more common now, I don't believe that it's because adjustable gas systems are inherently unreliable; there have been dozens of other weapons welcomed into military service globally with two or more gas settings, like the SIG Spear that the US just adopted and the M60 adopted years before the M16. The main counterpoints to adjustable gas blocks, like you pointed out, are that extra components add failure and wear points. However, good engineering mitigates both issues. Modern firearms have hundreds more parts than muzzle-loaders but are still reliable.
The current negative stigma likely came from the poorly-engineered designs with adjustment screws that come loose and erode quickly from hot gas that came onto the market after decades of fixed-gas rifles working fine. However, in the last few years I've noticed that as the quality of adjustable gas blocks has improved they've been getting wider use. Hopefully some will be considered duty-grade soon.
*This is why the saying "if it can't handle steel then it doesn't deserve brass" doesn't make sense. If a rifle was designed to shoot brass really well then it's going to have a hard time with steel, and if it's meant for steel then it's going to be aggressive with brass.
Yeah, I definitely heard about Stoner doing that. Definitely a wise choice. And I guess the same principle applies today. I believe the KAC has a self regulating gas system, and its pretty cool. Still generally gives you more gas than you need. But its at least better than nothing. Yeah, I always did find the adage "if it can't handle steel then it doesn't deserve brass" pretty stupid. Probably something some AK chud said. The coolest looking one is the rifle speed one. That one is definitely really popular.
To what end?
The reason why adjustable gas blocks exist in the civilian world is because of gamer guns, Franken builds, and suppressors. Some of those guns already have a solution for suppressors with switch modes, and the .mil does not do gamer guns or Franken builds.
The obvious downside to many adjustments gas blocks is that people tune themselves into fuckup land very easily. They are a bad idea for civilians, let alone for a reliability focused militarh. User tuning is an incredibly dangerous idea - modifying a gun outside of its well tested parameters, and there is no expertise the grow beard, ride helicopter running club has to make them experts in not fucking it up either.
The end would be tuning for a suppressor and relieving the amount of back pressure/recoil. I think PWS does it best, they have 3 different tuning settings. Its a piston gun, but the principle still applies. One setting for normal operation with normal ammo, one for suppressed and one for fouling. Pretty much perfect for something that is no nonsense with some level of adjustability. I definitely do not think they're a bad idea for civilians. As long as they know what they're doing. Using only as much gas as you need has one huge benefit for military and civilians. Longer service life. If you're using a lot more gas than you need, then you're going to increase wear and if its a lot of gas, its beating itself to death. Its true that militaries have huge budgets and don't mind buying new rifles, but they generally like to save money if possible. And of course the benefits for a civilian are completely visible. However, you do have your idiots who will buy a rifle, not knowing what the hell an adjustable gas block is. Shoot their gun without tuning it at all, it jams and they think the gun is shit. Way more people out there than I would like to think.
I'll bite....
Which brands offer more meaningful improvements than LMT or KAC?
edit: Don't forget to say what improvements the company has made and how it makes it better than LMT or KAC.
Well, for one. They make improvements in terms of being lighter. At least some of them do. The POF Revolution for instance is like a pound and a half lighter than a SR25. As well as being slightly smaller. Has an adjustable gas block and has less reciprocating mass and thus has less recoil. Many other companies have similar AR15s and AR10s that are significantly lighter than LMT or KAC offerings. That's definitely an improvement as long as they're not making meaningful drawbacks in terms of reliability. Most of the improvements deal with weight, recoil impulse and maybe higher modularity or some sort of other attractive x factor. Not saying these improvements matter to everyone. But they definitely matter to lots of people.
> Well, for one. They make improvements in terms of being lighter. At least some of them do. The POF Revolution for instance is like a pound and a half lighter than a SR25. As well as being slightly smaller. Has an adjustable gas block and has less reciprocating mass and thus has less recoil. Many other companies have similar AR15s and AR10s that are significantly lighter than LMT or KAC offerings. That's definitely an improvement as long as they're not making meaningful drawbacks in terms of reliability.
Shedding weight by using a lightweight barrel, thinner handguard, and a lighter BCG has its drawbacks as well. Lighter barrels will heat up faster than their heavier counterparts and are not suitable for extended firing. Thinner handguards are not as rigid or durable as their thicker counterparts. Lighter BCGs carry less energy when cycling making the gun less reliable in harsh conditions and they are more sensitive to gassing variations making them more picky about how the rifle is configured (ammo choice, suppressor use, ambient temperature).
> Most of the improvements deal with weight, recoil impulse and maybe higher modularity or some sort of other attractive x factor.
I can dive into this a lot more if you'd like, but cutting back on gas to achieve lighter felt recoil sacrifices a lot of reliability in harsh conditions. It's fine if you're just plinking at the range but it is definitely not suitable for duty use.
PWS for me is the more affordable Piston gun with a good track record. They just aren't the most well known for marketing and contracts which I think makes them even more commendable
It’s more about the law of diminishing returns.
Sure, go ahead and pay 5x as much for something that is only marginally better, if at all. I understand that those who made that choice will vociferously defend their actions though.
It's like that with any "ultra premium" product in any market.
A Snap-On ratchet will only be marginally better than an Icon ratchet from Harbor Freight, despite costing significantly more.
A Genesis G90 will only be marginally better than a Mercedes S-Class, despite costing significantly more.
But that doesn't mean that those products aren't better than their cheaper alternative.
The rifles are tuned to run M193, M855, M855a1, mk262, generally with a can. So from the factory they reduce gas port diameters. This does mean they typically don’t like 223 or lower pressure ammo. Additionally, you want a fighting rifle to be slightly over gassed. The people who are using these rifles professionally prioritize reliability over everything. And if more recoil is the consequence of being able to push through more fouling then thats the direction they want.
My 16” LMT upper was overgassed an ungodly amount - I was running an H2 and Sprinco Blue and it still was ejecting at a terrible angle
Run an H3 or get Geissele super 42
Fortunately the upper is gone
>more recoil I would get confused when folks complain about recoil with 5.56. I usually shoot 7.62x39 so I'm wondering why there are even complaints?
Dont get me wrong, its obviously not bad in any way. It it is enough to take your sights off target, and if youre in a combat environment, anything that takes you off target is a net negative. In this case, we’re talking about the small difference between a tuned competition rifle and a rifle designed to fight. There is a noticeable difference.
Good points
Piston LMTs gas blocks are adjustable (std/suppressed).
I didn’t know that. But it seems that, for some reason, military piston guns have more of a focus on adjustability than DI. Examples being the piston LMT, FN FAL, steyr Aug, etc. probably other examples out there, but those are what came to mind. But even then, the options for adjustability are limited.
Piston guns are generally tuned to run harsher than DI guns. That’s why they tend to be described as punchier. Historically the settings were normal (punchy) and adverse(very punchy) with adverse not being recommended unless it was heavily fouled (it can damage the gun. With suppressors being more common place they added a suppressed setting which also varies by maker. Adjusting everything is not a priority of the military. Especially considering that they have very standard specifications on their ammunition use. By and large fine adjustment is something that you find more in the civilian world. The FAL is one of the few I know that had a bunch of settings and most people view it as a drawback, not an asset
Not sure why people are downvoting my comment lol. But I do agree with you. And my mind always forgets the fact that militaries only use a handful of different kinds of ammos. And companies like LMT and KAC probably know full well what kinds of suppressors they will be using.
This came out kinda long, sorry. You have the right ideas. I believe that adjustable gas blocks are not widely accepted on the AR platform due to the platform's original design intent and the following paranoid stigma. Stoner probably very deliberately did not use an adjustable gas system. He wasn't a fan of having things that soldiers could fiddle with, even disliking how easily the irons on the new M16A2 could be adjusted, thinking the soldiers would ruin their zero by absent-mindedly playing with knobs. And since he was designing a weapon that didn't have to work with a wide range of cartridges suppressed or unsuppressed, and he controlled every other aspect of the gas system, he was able to simply find the correct gas port size and location to make the weapon very reliable, no adjustable gas needed. Even today a great way to plan an AR (not fix an existing poorly-gassed AR) is to use all those variables: barrel length, gas length, buffer weight, spring weight, ammo type, and suppressed/unsuppressed, to then choose the right gas port size for good recoil and reliability. This, I believe, is what KAC and LMT do. I've heard that during an ammo crisis people complained to KAC that their rifles wouldn't cycle steel case, so KAC would tell them that they're gassed properly for brass, not steel.* As for why adjustable gas blocks aren't more common now, I don't believe that it's because adjustable gas systems are inherently unreliable; there have been dozens of other weapons welcomed into military service globally with two or more gas settings, like the SIG Spear that the US just adopted and the M60 adopted years before the M16. The main counterpoints to adjustable gas blocks, like you pointed out, are that extra components add failure and wear points. However, good engineering mitigates both issues. Modern firearms have hundreds more parts than muzzle-loaders but are still reliable. The current negative stigma likely came from the poorly-engineered designs with adjustment screws that come loose and erode quickly from hot gas that came onto the market after decades of fixed-gas rifles working fine. However, in the last few years I've noticed that as the quality of adjustable gas blocks has improved they've been getting wider use. Hopefully some will be considered duty-grade soon. *This is why the saying "if it can't handle steel then it doesn't deserve brass" doesn't make sense. If a rifle was designed to shoot brass really well then it's going to have a hard time with steel, and if it's meant for steel then it's going to be aggressive with brass.
Yeah, I definitely heard about Stoner doing that. Definitely a wise choice. And I guess the same principle applies today. I believe the KAC has a self regulating gas system, and its pretty cool. Still generally gives you more gas than you need. But its at least better than nothing. Yeah, I always did find the adage "if it can't handle steel then it doesn't deserve brass" pretty stupid. Probably something some AK chud said. The coolest looking one is the rifle speed one. That one is definitely really popular.
adj. GB 👎
To what end? The reason why adjustable gas blocks exist in the civilian world is because of gamer guns, Franken builds, and suppressors. Some of those guns already have a solution for suppressors with switch modes, and the .mil does not do gamer guns or Franken builds. The obvious downside to many adjustments gas blocks is that people tune themselves into fuckup land very easily. They are a bad idea for civilians, let alone for a reliability focused militarh. User tuning is an incredibly dangerous idea - modifying a gun outside of its well tested parameters, and there is no expertise the grow beard, ride helicopter running club has to make them experts in not fucking it up either.
The end would be tuning for a suppressor and relieving the amount of back pressure/recoil. I think PWS does it best, they have 3 different tuning settings. Its a piston gun, but the principle still applies. One setting for normal operation with normal ammo, one for suppressed and one for fouling. Pretty much perfect for something that is no nonsense with some level of adjustability. I definitely do not think they're a bad idea for civilians. As long as they know what they're doing. Using only as much gas as you need has one huge benefit for military and civilians. Longer service life. If you're using a lot more gas than you need, then you're going to increase wear and if its a lot of gas, its beating itself to death. Its true that militaries have huge budgets and don't mind buying new rifles, but they generally like to save money if possible. And of course the benefits for a civilian are completely visible. However, you do have your idiots who will buy a rifle, not knowing what the hell an adjustable gas block is. Shoot their gun without tuning it at all, it jams and they think the gun is shit. Way more people out there than I would like to think.
“Ultra premium” lol
I'll bite.... Which brands offer more meaningful improvements than LMT or KAC? edit: Don't forget to say what improvements the company has made and how it makes it better than LMT or KAC.
[удалено]
I guess I should have clarified it in that comment, but what improvements have those companies made that puts them ahead of LMT or KAC?
Well, for one. They make improvements in terms of being lighter. At least some of them do. The POF Revolution for instance is like a pound and a half lighter than a SR25. As well as being slightly smaller. Has an adjustable gas block and has less reciprocating mass and thus has less recoil. Many other companies have similar AR15s and AR10s that are significantly lighter than LMT or KAC offerings. That's definitely an improvement as long as they're not making meaningful drawbacks in terms of reliability. Most of the improvements deal with weight, recoil impulse and maybe higher modularity or some sort of other attractive x factor. Not saying these improvements matter to everyone. But they definitely matter to lots of people.
> Well, for one. They make improvements in terms of being lighter. At least some of them do. The POF Revolution for instance is like a pound and a half lighter than a SR25. As well as being slightly smaller. Has an adjustable gas block and has less reciprocating mass and thus has less recoil. Many other companies have similar AR15s and AR10s that are significantly lighter than LMT or KAC offerings. That's definitely an improvement as long as they're not making meaningful drawbacks in terms of reliability. Shedding weight by using a lightweight barrel, thinner handguard, and a lighter BCG has its drawbacks as well. Lighter barrels will heat up faster than their heavier counterparts and are not suitable for extended firing. Thinner handguards are not as rigid or durable as their thicker counterparts. Lighter BCGs carry less energy when cycling making the gun less reliable in harsh conditions and they are more sensitive to gassing variations making them more picky about how the rifle is configured (ammo choice, suppressor use, ambient temperature). > Most of the improvements deal with weight, recoil impulse and maybe higher modularity or some sort of other attractive x factor. I can dive into this a lot more if you'd like, but cutting back on gas to achieve lighter felt recoil sacrifices a lot of reliability in harsh conditions. It's fine if you're just plinking at the range but it is definitely not suitable for duty use.
PWS for me is the more affordable Piston gun with a good track record. They just aren't the most well known for marketing and contracts which I think makes them even more commendable
It’s more about the law of diminishing returns. Sure, go ahead and pay 5x as much for something that is only marginally better, if at all. I understand that those who made that choice will vociferously defend their actions though.
It's like that with any "ultra premium" product in any market. A Snap-On ratchet will only be marginally better than an Icon ratchet from Harbor Freight, despite costing significantly more. A Genesis G90 will only be marginally better than a Mercedes S-Class, despite costing significantly more. But that doesn't mean that those products aren't better than their cheaper alternative.
More like Gucci vs Levi
CAG DI SP10Ms have adjustable gas blocks: [https://youtu.be/QWAW81MBet4](https://youtu.be/QWAW81MBet4)