This spring is 1.5" long, .042" wire diameter and the ends are squared and ground flat to compress straight and even. Being shorter than the factory spring, it produces more power and better shot consistency with less hammer bounce while remaining relatively easy to pull the bolt back. It works well without a power adjuster. If pre-loaded with a power adjuster it tends to be too strong and can damage CO2 models in cold temps which lowers CO2 pressure, when CO2 is running low and if you dry-fire. Using our .038" WD spring and/or one of our custom power adjusters is highly recommended to reduce spring tension when shooting with CO2 in cool temps.

Our power adjusters and hammer springs are extremely popular with experienced custom builders and serious shooters. They allow you to fine-tune spring tension for the best balance of performance, accuracy and efficiency with the widest range of adjustment in the industry.

The more hammer-spring tension you have the harder it becomes to pull the bolt back. It works the smoothest if you hook your finger around the handle close to the breech and pull back in one quick motion. More hammer-spring tension also increases trigger pull. We have custom triggers, trigger springs and sears listed that reduce pull, increase comfort and accuracy. For the lightest possible pull and best overall performance use the minimum amount of hammer-spring tension needed to get the power level you need. If going for maximum power use only enough tension for the power level to peak, variable-pump and CO2 models tend to lose power if the hammer spring is too strong because it will cause the valve-stem to cycle too fast for the valve to empty effectively. This can also happen with PCP and HPA if running in lower pressure ranges.