Adjustable Gas blocks for AR-15

[IndianaBoy]

I have used adjustable gas blocks for several years now.


I have a rifle with JP LMOS components for 3-gun and an adjustable gas block is useful for reducing gas to further enhance the lessened reciprocating mass.

I used an old JP set screw design, and currently have two of the Syrac which have detents and are click adjustable. Syrac is no longer in business but I am very happy with the products. One is on a 3-gun rifle that is tuned to nearly eliminate sight disruption . The other is used in a rifle with a silencer that is overgassed due to the additional backpressure when fired with the silencer attached.


If you are using a standard AR-15 and standard components, they really aren't necessary. Take things outside of the design envelope, and they can be quite useful.

 

[IndianaBoy]

Jackal,
Sound advice. I appreciate the offer but I think I will do the SLR as you did. My set up is similar to yours and I ain't going to argue with success. I think I will start wearing chemical goggles the next time I shoot with the can---that blow-back is a bitch.
Thanks from the deep South and keep your powder dry.
Dan

Adding an adjustable gas block dramatically reduced gas blow back on my 16" mid length. My theory is that properly regulating the gas, delays the bolt from unlocking long enough to allow the gas trapped in the bore and silencer to equalize more with the ambient pressure.

No more squirt of gas around the charging handle.


I knew it was overgassed due to how it recoiled, I added the gas block to fix that. I didn't expect it to reduce gas to the face but it did, dramatically so.

 

[IndianaBoy]

I put a drop of Kroil on the adjustment screws for my gas blocks every once in a while. A few hours later I will turn them in and then out a few clicks. I count the clicks to return them to their proper setting. Never had one freeze up, nary a problem using this method.

 

[Telekinesis]

I don't see how an adjustable gas block would cause gas keys to shear off?


Since they can only reduce gas, not increase it. The only way that I can see this happening is with improper installation causing the carrier key to impact an improperly centered gas tube. It is an easy enough thing to do. It doesn't take much misalignment to cause some contact there.

I would venture a guess that your fourth example may not be centered over the gas port on the barrel.

I misspoke. It was not the gas key on the top of the BCG, but the screw on the gas block that you turn to increase/decrease gas flow that snapped.