Hello AllI have a current production Daisy 25 and power was pretty low. The gun in stock form would produce 268fps with std daisy bbs. The power was a bit better with the Daisy ground shot at 280.I cut down a 111-40 spring and now it produces 350+ fps with standard Daisy bbs and 360+ with the ground shot.I figured this may help someone who is in search of classic power levels in a modern gun.
A little more detail.The 111-40 spring was purchased from JG. It measures 9 3/8 long.The wire gauge measures at .089. To get it to fit AND cock I cut off 5-6 coils. Then heated and flattened the ends. Finished by grinding end as flat as possible. I also made up a custom abutment washer. Its flat and stiffer than the oem washer. I really don't think that helped much though. Oddly the airtube is stock diameter all I did was deburr it. It is noticeably harder to cock but not too bad. Accuracy is in my opinion very good.
Just a FYI….my new model 25 with adult RR stock hits a tin can hanging at 30 yards ….thats good enough for this simple man….Tinker on dudes….good luck