So with the mbt2s trigger I was having light strikes on some Chinese brown cases ammo I had with the head stamp 71 over 82. It was firing everything else fine.
So on a hunch I ordered a red x firing pin and when it came in I compared it to the psa one. It was the same length but appeared to have a beefier tip on it.
So then I removed the psa h buffer that weighed 3.2 ounces and replaced it with a spikes tactical t2 buffer at 4.5 ounces with the 308 spring.
Im happy to report it now flawlessly ignites the brown cased Chinese as well as everything else I put through it.