An adjustable gas block will only work if your rifle is over gassed because of the port size or the powder type being used. Most malfunctions on a new build are not caused by over gassing but by poor assembly, inferior parts or assembling with the wrong parts. If your rifles gas port is too small no adjustable gas block will help. My AA 18" Grendel barrel came with the gas port over sized. At first I thought it wasn't getting enough gas since the shot casing wouldn't even eject out of the upper receiver and when it did it wouldn't pick up another cartridge. I adjusted my front sight "non adj gas block" so the gas port was not alined square with the gas port thus sizing down the gas port. To my surprise the rifle functioned. If the rifle is over gassed the BCG will cycle so fast it will not pick up or eject the casing which is what happened to me. I also had a 5.56 Bushmaster barrel that came with a small gas port which would function with only spec 5.56 ammo but would not function with lighter American eagle or HS ammo.
I like adjustable gas blocks because I can fine tune most ammo with any of my rifles. If your barrels port is too small you must only use ammo that is proven to be reliable with that port. Adjustable gas blocks work great for fine tuning loads and preventing excessive recoil or as in my case fixing a over sized gas port. Both the Syrac or the SLR "my favorite" gas blocks have worked perfectly with my builds. I have both the screw type and the clamp on gas blocks and both have worked flawlessly but I will only use the clamp on SLR for my future builds if space under the hand guard is not a problem.
The adjustable gas key maybe another alternative to the adjustable gas block and cheaper.
I like adjustable gas blocks because I can fine tune most ammo with any of my rifles. If your barrels port is too small you must only use ammo that is proven to be reliable with that port. Adjustable gas blocks work great for fine tuning loads and preventing excessive recoil or as in my case fixing a over sized gas port. Both the Syrac or the SLR "my favorite" gas blocks have worked perfectly with my builds. I have both the screw type and the clamp on gas blocks and both have worked flawlessly but I will only use the clamp on SLR for my future builds if space under the hand guard is not a problem.
The adjustable gas key maybe another alternative to the adjustable gas block and cheaper.