LRRPF52 Wrote:The main reason not to use adjustable gas if you don't need it is port erosion.
You just took an open port and put a choke over it, turning it into a combustion chamber rather than the outlet for a manifold. There are ways to counteract that with nitriding and other processes, but I personally don't use Adjustable Gas if I don't need it.
OK, I misinterpreted the above statement. I thought you were advising the poster.
I realise there's some back-peddling going on but let's be clear about one thing, port erosion is a non-issue to end-users of the AR15. It's an impressive-sounding topic but as soon as it starts to influence product choices that's when we need to put the brakes on with a reality check. As far as barrel life, accuracy and reliable cycling is concerned port erosion affects none of them. If adjustable blocks erode the port faster than non-adjustable blocks (and I am still unconvinced of this) then this means precisely nothing when compared with normal barrel wear-and-tear. Notwithstanding, the barrel wears more at the throat and early lands, coinciding with the peak pressure spike. Not down at the port when the pressure has dropped.
My advice to the op is get whatever block you like. They all work. With a suppressor an adjustable gas will help govern the gas to a level that is more user-friendly, but it is not critical in most cases. If you suspect your gun is over-gassed even without a suppressor then an adjustable gas will fix that also. Without the need to resort to full-mass BCG's and heavier buffers.