Dont know about Accupells.

I read somewhere that Umarex test the Peacemakers to 2500 rounds.
Not much compared to the old Crosman 600s which were cycled on test rigs for hundreds of thousands.

The truth is that most modern co2 guns are not built to last and many cant be repaired.
The exeptions being the original Umarex pellet firers CP88,1911 etc.

But I hope yours can be sorted.