School me on adjustable gas blocks

[peak98]

[Mhan7]

I like to keep this explanation simple, until you have more questions or more details are warranted. Quite simply, an adjustable gas block is seldom needed when not running dual modes (i.e., suppressed or unsuppressed) - but its use is another parameter that you can control. You have several ways that you can soften the recoil, and reduce the banging and clanging of parts.

An overgassed gun is just slamming a chunk of steel into your buffer tube. The idea of adjusting the mass, is create resistance. Newtons' law - you're creating a load that has to be reacted, for the action of the bolt carrier cycling. Now, there are MULTIPLE ways to do this. You can play with mass, you can play with gas, and you can manipulate spring tension.

Adjustable gas blocks are just one way. Depending on how accessible they are inside your handguard, they may not be the best option. There are some great choices for easy switching - but they still might not be right. Some are 100% preset. Meaning, you are changing the size of the orifice, by way of an interface between the gas tube and the port. An example of this would be the Strike industries collar adjustable gas block. Others use a lever. Seekins precision makes one of these. It also has an infinitely adjustable setting to optimize your gas BEFORE you throw the lever to the suppressed position. Then, there are adjustable blocks like the JP detent adjustable, which is meant to be set up for a gun that gets shot the same way all the time. That's for the shooter who wants to dial in the perfect balance of cycling (which some people adjust per load, btw), with the least amount of felt recoil.

There are also adjustable bolt carriers, and gas keys. These are generally more user serviceable. Bootleg makes an adjustable carrier, Rubber City Armory makes an adjustable gas key.


Adjustable gas blocks, carriers, and keys, all serve the same basic function. If you don't have to shoot a lot of rounds fast, a gun that just "barely" cycles can sometimes be really nice. On the other hand, an overgassed gun can be a monster.

If you have a mil-spec gun and no suppressor, probably a waste of time. If you have a precision gun, and longevity of parts, and low recoil (i.e., staying on target for a follow up shot) are important to you, an adjustable gas system of some sort. isn't even a question.

There's more nuances to the conversation, when you start getting into playing with gas systems, the lengths of tubes, trying to get more dwell and lock time, etc... But that was the basics.

[Mhan7]

Now, this is just my opinion, but I'll tell you what I like for a gas gun that has no real pedigree... I have a "trunk gun" that's got a shorty barrel, and uses either a CQB or Kaw Valley Linear Compensator (I swap them out). I'm running a JP Silent Capture Spring - not the H2 model - and a Strike Industries Collar Adjustable gas block, which can be rotated with a car key, through an M-Lok slot. Gives the option to run wide open or shut down for suppressor, with 5 easy presets. It's more than adequate. That's 1 wide open setting, 3 various size "other" gas orifices, and one off position. (should you decide to single shot)

Those other settings are nice when you try new ammo, or when you shoot in different conditions. (winter vs summer) You may love it, you may not be arsed to bother. I don't know, but I am very particular about being able to adjust and customize my stuff, and the only disadvantage I see, is that you either have to trust someone else's advice, at your own expense, or you might miss out. I might suggest asking around and seeing if anyone can demo an adjustable gas block for you. You can do as much (or more) with gas blocks, as you can with springs. Both options seem to cost about the same, on the average.

[Mustangfreek]

If you already have it, put it on and tinker with it.

I myself find this aspect just as fun as the shooting aspect

[A5BLASTER]

Here it is nice and simple to follow.

You dont need it but if you dont use it be sure you use a full weight bcg, a stiff buffer spring and have several heavy to very heavy buffers on hand. Because it's going to be overgassed.

Now if you use it, the normal carbine buffer/spring that came with the brace will work just fine, set it so it just cycles and locks the bcg back on empty mag.

If you want the full effect you can also drop a lowmass bcg into your pistol with the adjustable gas and the gun will run even better.

Heavy buffers and stiff springs are for controlling gas levels when it's not adjustable.

Adjustable gas blocks, lowmass bcgs and jp scs are much more smooth running, even when cycling by hand.

I have done 12's 12.5's 16, 18, 20, 22, 24 inch grendels both ways heavy buffers and stiff springs as well as lowmass, hp scs and adjustable gas.

And the adjustable gas, lowmass setup wins every time as far as running smooth and clean, less felt recoil and just a overall better feeling gun.

[montana]

The reason I use adjustable gas blocks," is to fine tune my rifle" to the ammunition I use. When the gas is set to optimum for the ammunition, "the recoil is soft and smooth for faster follow up shots" and the less wear and tear occurs with the rifle. When a rifle's gas port is set up to use true NATO spec ammunition, the rifle may not run reliable with other brands of ammunition. Many barrel manufacturers use over sized gas ports, to reliably run the lower end manufactured ammunition on the market. If your rifle will run reliably with steel case ammunition such as Tula or wolf, then your rifle will be over gassed with Mil spec surplus ammunition. An adjustable gas block will work better with an oversized gas port, since the adj gas block can only restrict the existing gas port.
The down side of an adj gas block is they need maintenance, "meaning a drop or two of oil and then turning the screw in and out full range after shooting" to prevent carbon lock with the adjustment screw.. I have used many types and prefer the SLR, since they are easy to disassemble and clean. That said, "I'm now experimenting with the Superlative Arms "Bleed Off adj gas block" since they claim it will never carbon lock. So far so good, but I will need more bullets down range to verify this claim. The other down side is the need to set the gas block correctly for colder temperatures and as the action becomes dirtier.
With the optimum gas setting, bolt carrier type and recoil buffer system, "the AR can become an amazing, soft shooting, platform" many need to try to appreciate..This works with any AR caliber, and barrel length...

[peak98]