Need info on HW77 fps

[JOSEPHVILLE GUN]

I have a friend who has a HW77 and is shooting RWS Diabolo Basic 7.0gn pellets he is getting around 580 fps on my chronograph . We are wondering what he should be getting. This is an old rifle that was purchased used. Do we need to install a Vortek kit in it or is it ok the way it is.
Shane

[eeler1]

No, not ok, unless someone tuned it that way for some reason.  Should be at least 825 fps, much higher actually.  Test the chrono with another known gun.  But yeah,  I predict some new innards in your friends future.

[JOSEPHVILLE GUN]

Thanks I was not sure what it should be.
Shane

[Tomcat]

This link will give you data for the HW97 which I believe is the same innards.  Good reference for all types of pellets.  Go to the "Our Take" tab if it doesn't come up and you will see all different pellets and their data.

http://www.straightshooters.com/beeman-hw97-beech-.177.html

[T-Higgs]

My 97k is shooting .20cal 13.7 at 715-720 FPS = about 15.5 FPE. 580 seem too low.  I think that's slower than a R7.

[grauhanen]

It is shooting with much less than 12fpe.  Maybe the piston seal needs a little bit of silicone oil -- a few drops through the transfer port.  Work it in by "pumping" the piston.  See if that helps by shooting over the chrony.  If that doesn't make any difference you will have to open it up and put in a new spring and seal.

[Booger]

Should be 860 range with an 8.44 pellet. That puts it in the 14 FPE range. JMHO

[gard72977]

If this is a old 25mm piston gun the FPS will be lower than the new one. They would usually run in the 10.5 to 11 FPE range. I was shooting 7.87gr pellets at 775 FPS if I remember right. The 25mm is a smooth and accurate gun but does not produce a lot of power. I really enjoyed my 25mm HW77 and regret selling it.

[palonej]

My 97 is shooting 8.64 FTTs around 880.
Sounds very low!!