Tuning .22 FX Dreamline conversion to .25

[uhfradarwill]

My Dreampup currently, with the extended plenum, shoots JSB 18 grain pellets very, very well at ~ 950fps.

My question is has anyone converted theirs to .25 cal? If so, can you get the speed up to around 950fps?

My reg is at 130 and the hammer spring is almost at max.

How was the grouping?

Thanks

Will

 

[Jlowe]

I think you'll have to add the .25cal hammer weight as well. My Dreamline Lite .25cal will shoot 975 with a power plenum and Huma pin probe at 145 bar. That's with a. a JSB 25.39. It has the old Pellet transfer port, so with a new Huma dual transfer port coming next week it should do 985-990 without upping the reg. It went up 20fps just by adding the Huma pin probe. 910 tuning maxed one out with a power plenum at 1000 or so at 160 bar and 1020 with 2 plenums. I can't remember exactly but they have a Youtube video on it. 





https://www.youtube.com/watch?v=E4wSGNbE10Y









https://www.youtube.com/watch?v=3wD6U6epYz0

 

[Soloshot]

I converted a .22 to .177 and had to purchase the lighter hammer weight (after a lot of head scratching). Going from .22 to .25 will be ok using the existing .22 hammer weight. There was a serial number correlation to hammer weight part number thread some time ago.