Safety BB missing (Troubleshooting)
It can be replaced by a small stainless steel “BB” broken off from the Dog Tag Chain.

Safety BB spring (Troubleshooting)
It can be replaced by a part of the tank O-ring that is cut into to the same length as the spring.

Break balls (Troubleshooting)
Polishing the Barrel and replace the Bolt will fix it.

12-gram not being pierced (Troubleshooting)
The piercing pin might be damaged or wore out, get a replacement. Or properly due to a weak main spring or the velocity adjuster being backed out to far. – Lee

All shots are low-powdered (Troubleshooting)
The piercing pin might be damaged or wore out, get a replacement.

Leaking down barrel (Troubleshooting)

PunishersCustoms wrote:
First, you may have a jammed or broken valve spring. If it doesn’t push the valve pin closed, it’ll leak like a pig…. Next, you may have some dirt on the cupseal or even a damaged cupseal. The worst thing I can think of would be the valve pin being bent. If one of the previously stated problems caused it to seize in its bore, the thing could be tweaked. You’re best bet is to pull it apart and root around for the problem….. drop me a line if you need assistance.

Why is the first shot of a new 12-gram so slow? (Troubleshooting)
Unlike most 12 gram powered guns, the Sheridans do NOT pierce the cartridge when you screw down the front cap. The piercing pin is actually on the cup seal, and pierces the 12-gram when the hammer drives it forward on the first shot. That’s why the first shot is always low powered. You can turn the gun upside down and cock it without loading a paintball so you don’t waste one with that first shot, or there are a couple of modifications that you could do. Ask the custom shops for more details.