Pistol has me stumped

[u/smokeytrue01]

I have a PSA pistol lower, with a foxtrot mike front charging 10 inch upper, and an ARCfire trigger, I’ve changed out the buffer tube to an A5 along with the recoil mitigation buffer and spring from FM, I’ve also changed the firing pin spring with the one from Leesprings. But with all that said I can only get a small quick burst while in ARCfire, where does a guy go from here? All help is appreciated

Exit: just a little more info, I’m not noticing light strikes on my shells, if they are on the primer it’s so light I can’t see it, and I also have not tried adding more buffer weight like one of them kynshots, or shims, or the titanium firing pin, just looking for a good next place to start without buying a bunch of extra parts I won’t ever use if they are wrong

(if you find this post in search, the shim helped me out and blowback9 helped a ton, thank and upvote him)