The Crosman 22xx series valve can be modified to either increase or reduce power.
Reduced Volume Valve
For shot count and consistency along with a calibre change from .22 to .177, Crosman chose to use a modified reduced volume valve in it's target range the 2300s and 2300T.
The reduced volume valve shares the same external dimensions as the standard 22xx valve but has intenal differences.
The Crosman EVP shows the below changes:
Valve stem G397-013 has longer brass platform than the 2250-016 stem (14.88mm v 12.17mm)
Addition of spacer 2300-037 - 9.93mm Long x 13.3mm OD x 11.04 ID
Assembly Stem Guide 2250-020 (Front part of valve)
(Valve body, spring and seal are common to both valves)
Increased Volume (Power) Valve
The main way to increase power via the valve is to increase the internal volume, shorten the thread on the Stem Guide and to angle the valve exhaust port.
Though this is possible to do with a dremmel it is advised to let a skilled machinist perform the task on a lathe. It costs so little to have done is it worth damaging a valve ?
You will see in the picture to the left the material that can be removed from the valve body.
In the UK a machinist should charge you between £15 and £20 to modify your own valve and I can recommend a dude called David Thompson. (aka Peasngravy) Contact me for his details.
For reference a standard valve weights around 95g, a modified valve around or below 85g
