Fenix 400 trigger sear problem

[Toxylon]

A while back I bought a used Cometa Fenix 400 from 2004. I shot the gun as is for a couple of dozen shots. It performed fine, albeit underpowered, due to a worn out mainspring. I especially liked the fine trigger.

A couple of days ago I replaced the mainspring and piston seal, and de-greased, de-burred and re-lubed the gun, using only Birchwood Casey's Moly Lube on the insides, and none on the trigger mechanism. Break-in period commenced.

I have shot the repaired gun now app. 150 times, and a worrying problem has emerged: every couple of dozen shots the trigger pull gets progressively lighter, until the gun doesn't cock at all. Then, pulling the trigger while the gun is uncocked moves some parts inside the trigger housing (by feel and sound). After that the gun cocks and holds normally, for a couple of dozen shots. Rinse and repeat.

It seems the trigger sear has trouble re-setting after a while, leading to partial and then absent engaging. Maybe some springs in the trigger mechanism need replacing? Maybe some critical surface has worn too much (unlikely, in my opinion)?


A gun with a faulty trigger is like a car with faulty brakes. This needs fixing asap, but I have never done any trigger work (apart from an antique direct-sear Diana Mod.25), and have little knowledge on the Fenix trigger mechanism. Any help with diagnosis and appropriate course of action is appreciated.

[mikeyb]

Maybe this will help?

https://www.tapatalk.com/groups/yellow/cometa-fenix-400-cocking-problem-t165346.html

[Mark 611]

AIRFORCE INTERNATIONAL is the U.S. importer for COMETA, if you need parts I would go there or Chambers, IMO if the trigger is starting to get soft and pulling thru it either set to light or possible the sear spring need to be replaced, the 1 in the back of the trigger housing

[Toxylon]

Big thanks to you guys! I'll have to delve into the very pertinent link by Michael. I'll report here how things turn out.

[Toxylon]

After reading the tapatalk link by Mike, I took the trigger system of my Fenix 400 apart. There weren't any cracked or excessively worn parts there. The only slightly suspect culprit was the upright spring behind the trigger - was it maybe fatigued?

As a first aid, I took the advice of the U.S. Cometa importer in the link, and tightened the trigger pull screw. It took the problem away, but only for a while - then the uncocking problem came back.

Re-checking the screw behind the trigger, I learned it had vibrated loose again, so I tightened it up as far as I could without mangling the screw slot.

Since then I've shot the Fenix for some 200 times total over several sessions, the gun has cocked every time, and the trigger screw has remained tight. Even maxed out, the trigger pull is well within my accuracy parameters. Problem solved, for now.

After dealing with the trigger I switched the bent original .177 cal barrel to a new .22 cal one. The bigger caliber fits the FAC-springed gun much better, and produces quite a bit more KE. Superdomes are the most powerful and also most accurate pellets so far.

I only wish Cometa hadn't spoiled their classic barrel design by adding the power washer-like plastic "supressor", which is ugly as sin.