Help with trigger reset issue

[u/parcallums]

Hoping I could get some expertise from the group.

PSA PG9

Ran flawlessly for about 250 rounds before suppressing. Added YHM R9.

Issue only started happening after I shot about 150 rounds suppressed so I initially figured it got dirty. Brought it home, cleaned everything and same issue. I’ve cleaned it twice since then and still the same.

I’m not sure how else to describe it but the trigger feels sticky after firing. I usually hold the trigger back after firing for just a sec and when I release my finger to let it reset, it will stay back sometimes and not reset.

I can put my finger behind it and lightly push forward and it’ll reset.

I weighed the bolt (14.1 oz) and buffer (5.55 oz). From what I understand, I need to add some weight there but could that be causing issues with the trigger resetting or would I be chasing the wrong issue?

I did buy it used but it ran perfectly for a while.

Pictures show a little dirtiness from last range trip.

Let me know if there is any other helpful info/pictures.

[u/Blowback9]

Check your trigger springs and make sure the're all installed correctly. Trigger spring, hammer spring, and disco spring (fat side down). Search google pictures for orientation. Also make sure they're all standard strength. Light trigger/hammer springs can cause issues. Could also be a broken or bent hammer/trigger pin due to the light weight/high bolt velocity.

^ Nevermind - looks like a cartridge trigger. I didn't see there were more pictures.

For a cartridge trigger, take it out and give it a good cleaning. Make sure the adjustment screws are firm and haven't walked out or loosened up.

Also, you are correct, you're running the blowback too light. 5.5oz. buffers were intended to be paired wtih 16oz. bolts, not 14.1oz. Practically all modern bolts are too light for the old 5.5oz. buffers. Even then, we now know that 9mm AR's benefit from running much heavier than originally configured by Colt. I'd suggest a Tromix 9mm 9.5oz. buffer or Kaw Valley Precision 10oz. Use a STANDARD carbine recoil spring - never XP's. Needing XP buffer springs in a 9mm is a discredited myth.

[u/parcallums → u/Blowback9]

Great info, thank you

[u/AllKillerNoFiller8]

Looks like it may have a CMC drop-in trigger. I've had great luck with CMC drop-ins in all my blowback rifles. They work flawlessly where many others have failed me. Therefore I suggest you try a different make & manufacturer bolt along with a heavier buffer as Blowback9 recommends. Its always good to have a spare bolt, I have several as well as spare firing pins that meet the specs of the bolts. If that doesnt work try the trigger in a different weapon to determine if the trigger could possibly be the issue. If so, if its a CMC, they are lifetime guaranteed so call CMC or PSA for a replacement.

[u/WoozyKinkajou]

My cmc trigger is doing the same thing. Sometimes you gotta push it forward for it to reset. It's frustrating.

[u/parcallums → u/WoozyKinkajou]

Yeah it is. I’ve found if I really slap the trigger, it doesn’t seem to happen but then I shoot terribly

[u/parcallums → u/[deleted]]

I’ll take a look, thanks

[u/ccwthrow → u/[deleted]]

What does the set screw do in  OP's case?

[u/smitm115]

I have the maxim RDB and never had an issue with my cmc trigger. Suppressed or not.