sumatra 2500 softer hammer spring

[419bobw]

I have a sumatra 2500 .22 caliber and would like advise as to where to get a softer hammer spring (other than stock) so that I can better shot string curves withe my air rifle

[Ribbonstone]

Usually the Sumatra does pretty well when dialed back with the power wheel, at least the old ones did (haven't played with the new ones).

Changing the spring also changes the pressure where it runs well (lighter spring tension working better at lower pressure) while the power wheel varies the valve stem available for the striker to hit (kind of like a variable bstaley set up).   This assumes the power wheel is still functioning correctly (sometimes it is stripped, so it just spins and doesn't do "jack").

[ScottB]

Read this thread. It is about the Evanix Rainstorm, not the Sumatra, but I think you will find information that will help you with your Sumatra.
http://www.gatewaytoairguns.org/GTA/index.php?topic=58511.0

[amb5500c]

Welcome to the GTA.
Richard