02-27-2015, 03:28 PM
It depends on the adjustable gas block. Most after market adjustable gas blocks, especially for the AR platform have a screw that blocks the gas port restricting gas flow. The screw will get a lot of carbon build up after use. I move my adj gas screw in and out every once in awhile to break up any carbon build up and so far I have had no problems. One of my main concerns is how long the screw will last from wash out from the highly heated gas. So far all my gas blocks have been working fine. Another concern is the coil spring used to index the adj screw setting. Coil Springs tend to fail under extreme high heat. SLR gas blocks have corrected this concern with a Titanium leaf spring which looks like a better design. I have seen adj gas blocks and adj gas tubes that have no way of locking the adjustment screw fail after the screw backed out under use. I avoid these types.
The FN FAL adj gas block avoids all these issues with an adjustable collar that increases or decreases the amount of gas impinging on the gas piston by increasing or decreasing the opening of the gas relief whole. I have seen these fail on a high round count full auto FAL where the collar expanded so much that it wouldn't seal the gas release whole no matter what setting it was on.
Only testing and use will prove the longevity of any design but I have had no problems with my Syrac or SLR gas blocks so far.
The FN FAL adj gas block avoids all these issues with an adjustable collar that increases or decreases the amount of gas impinging on the gas piston by increasing or decreasing the opening of the gas relief whole. I have seen these fail on a high round count full auto FAL where the collar expanded so much that it wouldn't seal the gas release whole no matter what setting it was on.
Only testing and use will prove the longevity of any design but I have had no problems with my Syrac or SLR gas blocks so far.