Hammer Follow...

[mrvip27]

Have a PSA AR-v custom build I did with a Taccom 3 stage buffer and I am getting major hammer follow...two/three shots.

Running a CMC 9mm pcc trigger. Looks clean. and disconnector test seems to work fine. (hold trigger push hammer, release check)

 

Ran fine for most of the match until about stage 6. Thought maybe the travel wasn't enough. Removed a spacer. Did test fire of about 20+ rounds double tapping in the bay...No issue..Temporarily fixed it but the issue resumed the following stage towards the end after about 20-25rds. Then i swapped to someone else's gun to finish the match.

 

The trigger reset every time and the bolt stripped the round every time.

 

Have never had this issue until this weekend. Been using this setup for over a year and a half without issue.

 

Any suggestions? Not sure how to fix this.

[Dirty_J]

When you say “removed a spacer”, what kind and how many did you have in there ?

 

I can’t imagine the dedicated PSA bolt is designed to run much shorter than a full stroke length. 

[mrvip27]

2 hours ago, Dirty_J said:

When you say “removed a spacer”, what kind and how many did you have in there ?

 

I can’t imagine the dedicated PSA bolt is designed to run much shorter than a full stroke length. 

 

Removed the delrin bumper at the end of the buffer

 

 

Edited April 11, 2023 by mrvip27

[Dirty_J]

Gotcha.  Are you also using the pre-load rings on the spring as shown in the photo? 
 

What ammo? What kind of power factor?  Been using the same ammo the last whole time? 
 

Hammer follow can also occur when the buffer mass/spring is too great for the ammo being used. It’s not just about the maximum physical distance it can travel… the buffer can also just run out of energy before going all the way back, causing hammer follow. 

Edited April 11, 2023 by Dirty_J

[mmchambers06]

Is the buffer adjustable? I had an earlier adjustable two stage buffer that over time adjusted itself into malfunctioning on a PSA AR-9.

[mrvip27]

2 hours ago, Dirty_J said:

Gotcha.  Are you also using the pre-load rings on the spring as shown in the photo? 
 

What ammo? What kind of power factor?  Been using the same ammo the last whole time? 
 

Hammer follow can also occur when the buffer mass/spring is too great for the ammo being used. It’s not just about the maximum physical distance it can travel… the buffer can also just run out of energy before going all the way back, causing hammer follow. 

 

S&B 124. HOT PF LOL. yes. same ammo entire time..

 

Yes, using preload rings. Just as pictured.

 

2 hours ago, mmchambers06 said:

Is the buffer adjustable? I had an earlier adjustable two stage buffer that over time adjusted itself into malfunctioning on a PSA AR-9.

 

Yes, but I have left it alone as it arrived because it has worked.

[Dirty_J]

Well. Yeah. If you’re shooting nato spec pistol ammo… it ain’t that.  
 

I’d be focusing attention back towards the trigger. 

[mrvip27]

13 hours ago, Dirty_J said:

Well. Yeah. If you’re shooting nato spec pistol ammo… it ain’t that.  
 

I’d be focusing attention back towards the trigger. 

 

I will update the thread once I get it figured out.

[rishii]

Send it back, cmc will take care of it

my cmc PCC trigger went from crisp and strong reset to mushy, sent it to them and repaired for free