Best upgrade i ever made - Adams Arms P Series Micro Adjustable Block Piston Kit

It is almost the same weight as a standard AGB, it's actually quite impressive. Very high quality product.

Works flawlessly, no modification to the kit or the op-rod required as others stated. If you are running into length issues - I would modify the barrel nut before trimming op-rod.

Only things I had to modify were

1. Non mil spec barrel nut had to be drilled out for proper clearance. Adam's Arms customer support were great and respond within a couple hours usually(SO to Philip Dawson, thanks for your help) sent me explicit instructions with pictures of my exact handguard barrel/setup.
2. Drill out and expand the dimples on my barrel, the set screws for this block are larger than standard and will not seat in normal sized factory dimples

My gas port is on the smaller side 0.084" and this will still cycle subs/supers and lock the bolt back with a standard buffer/spring unsuppressed. There's really a lot of adjustability when going suppressed and could even potentially go with a H3/T3 buffer and stronger spring if enough backpressure. If struggling can always drill out the gas port to 0.120" as a last resort, or go with a nemo arms 300 blk reduced power buffer spring if really struggling. Luckily I did not have to do that on my setup and it works flawlessly.

I have about 500 rounds through it since installation and it still has the lube on the bcg from when I installed it. This is way better than DI especially when running a suppressor.