5.56 SBR - Suppressed and Unsuppressed - Adjustable Gas Block Needed?

I've tried to search for the answer to this, but have come up empty - I'm about to start my 1st SBR build in 5.56 and came across the Noveske 10.5" CQB barrel w/Switchblock. I do plan on running suppressed, but not all the time. Since a suppressor affects the gas system, it appears there are issues trying to have a system capable of running both suppressed and unsuppressed (which, according to Noveske) the Switchblock solves. I'm not running full auto, only semi so the increased cyclic rate isn't a consideration.

A couple of noob questions - not my first AR build, but this is the first SBR I'm going to tackle (damn these things are addicting):

- Do I need an adjustable gas block for this configuration?

- Is the Noveske GTG or are there other, better options out there? I know the Switchblock has to be outside the rail, but I don't mind the look.

- I've never used or installed a pinned gas block - is this something I can do myself? I have all of the usual AR build tools (punch set, roll pin starters, AR tool, action blocks, etc). My other builds used set screw gas blocks so this is a new one to me.

Sorry if this has been beat to death - alternate thread references are welcome.

Thanks!

I have a RRA 10.5 SBR and have run it through a carbine course suppresed plus another 1000 rounds or so unsupressed, no issues whatsoever in either mode. The gas does tend to get more in your eyes when suppressed though..

I would only consider an adjustable gas block if it's going to improve my accuracy, as reliability is fine without it.

I use a Switchblock on several of my Rifles especially the 10.5 I have less Gas in my Face

I can only speak from one side since I've never used an adjustable gas block, but it seems like an answer to a problem that doesn't exist. My 11 1/2" runs fine suppressed or not. Just this past weekend, we camped out and through two days I ran probably 150 suppressed rounds and about 50 unsuppressed. That's not a huge round count, but it is still an indication of how the gun runs. I've always assumed that running suppressed is gonna be a little harder on the buffer and spring (especially since I run a standard buffer) but they are fairly cheap to replace and it's reliable so I hate to dick with it for no reason.

I remember reading somewhere that the adjustable gas block does make a difference on accuracy when running suppressed, can't find it but if someone has more details on the science of why or why not I'd be interested

I have a Switchblock on my Noveske 12.5", but I don't have a suppressor yet. Life's expenses got in the way.

My 11.5" Frankengun runs with or without the FA556AR on all ammo except Wolf. It will run perfectly on Wolf suppressed but turns into a straight pull bolt action when I take the can off. I don't think the issue is about reliability so much as durability. If my rifle runs fine unsuppressed, then the parts are experiencing more wear than necessary when I attach the can. Still, it is not likely to cause any problems for me for quite a while. I don't think I can afford enough ammo to make it a problem.

interesting, so you may actually benefit from the variable gas block in this case.. still curious WTH the variable gas block is intended for

As I understand it, the adjustable gas blocks allow you to fine tune the amount of gas coming through to cycle the bolt. With the standard gas block you adjust it to where it will still cycle unsurpressed while using the least amount of gas possible. That way, when you put a can on, you get a closer to normal amount of cyclic rate as a standard unsupressed gun and less gas blowback in your face. These adjustable blocks are really designed to be set once and left at that setting.

The Noveske switchblock actually has a 3 position setting. One for unsupressed where it allows the full gas through, suppressed setting that limits the amount of gas to compensate for a suppressor, and off for no gas so you can pretty much use the charging handle like a bolt gun.

I just bought the Switchblock since I like the option of the preset positions.

The regular adjustable use a set screw which would be hard to dial in on the fly for suppressed/unsuppressed.

Also, I don't think an adjustable would help the above poster with running the Wolf. They cannot increase the amount of gas beyond what the barrel allows to run underpowered ammo.

Oh and to answer the OPs question, if you buy the Noveske barrel with switchblock, it already comes pinned. You can use a punch to drift it out and back in. Just like driving out pins on an FSB.

The Switchblock is not necessary but it does have benefits when running suppressed. Less gas in the face, slowed down cyclic rate, less fouling in the gun, etc. it's just something you have to decide whether it's worth ~$200 for that benefit.

Got it - thanks for all the great insight and explaining the pinned gas block question I had. I figured that was it and come to think of it, I did drift the pins out of my first build (a retrofit)...

Basically what I'm seeing about the adjustable gas block is "not necessarily a must-have, but it smooths things out when running suppressed".

The extra money is certainly something to think about, but then again when I start adding up everything else I've got in the setup between the hardware and tax stamps it becomes less significant from a relative point of view. I can always eat raman and stare at all my stuff - maybe that will make it taste better...

Thanks again!

(Edited for spelling)

The ramen does taste a lot better this way. That's how my $700 budget bills turn into $2300 best of everything builds. But I still keep doing it. Lol

Ahhh Im not the only one with this problem!!

Anyways I run a H3 buffer & Oring on the extractor in my 10.5" Double Star. It runs great with or without my Phantom.

I haven't used mine with a can yet, but the sound to the shooter is noticably quieter with the gas block in the off position.

When my stamp comes (July will be 6 months), I may do some POV video in all three modes with some run of the mill ammos while using the can.

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