Gamo CFX .22 only shooting around 630 FPS

[SoCalFan]

Bought my CFX .22 from PA last October. A total of about 500 pellets went thru it. Had it chronied last week. It only registered around 630FPS using CP Dome. What could be wrong? I was hoping for low 700's. I know the chrony is fine, since my TX200 .22 logged in an average of 740FPS. Thanks for your feedback!

[preez]

Hi Ben, I don't think there's anything wrong with your CFX. First off, the CFX has similar powerplant to Shadow series, but the rotating breech makes the transfer port longer and loss of fps is expected. This seems to be affecting .22 cal more than .177 CFX, for whatever reason. Secondly, you mentioned that your rifle has only 500 rounds through it, which means it's not fully broken in yet. Give it another 500-1000 rounds and it should go up a bit. Lastly, the CP's have pretty tough skirts, try JSB's and see how they do.

And remember, it's not all about FPS! Consistancy and accuracy are more important.

Hope this helps

Chris

[shadow]

Chris is right the CFX.22 has the same powerplant as several other Gamo's and that's been about the average fps on them. Gamo re introduced the CFX.22 awhile back and pumped up the fps numbers as most airgun companies do.  :0 Myself and several other members back then snagged onto the .22 model and some were commenting on the low numbers but I must have got the a  exception to the batch  since mine sits right at 700fps. She's the only shooter in my stable that hasn't been tuned, shoot's to darn good and is accurate as heck. Ed

[Mark 611]

yep nothin wrong these rifles are real world velocity # are only 650ish so don't worrie I'm sure it could be made to shoot a little faster if you want but don't expect to much tho.

[SoCalFan]

Thank you, Preez and Shadow! You guys' feedback surely makes me feel better now...Will try another tin to see what happens next. Maybe a change of pellet, like JSB, might help boost up the FPS a little. BTW, my TX200 just loves CP Dome. As I mentioned in a separate thread, I returned the Leapers 3-12x44 SWAT that can't hold zero. I do enjoy shooting this CFX since it's not hold senstive at all compared to the TX200. A great off-hand shooter!

[SoCalFan]

Thanks for your input, Mark! I think I can live with 635-ish FPS, which is a good speed for targets within 40 yards. I had actually shot a starling out to 60 yards - laser-ranged. For long distance beyond 50 yards, my go-to gun is AA S410ERB .22. What a PCP! It will spoil any shooter! I also want a Daystate Airwolf, and need to start saving now:~(

[shadow]

I proper tune may give you some extra fps too but with mine sitting at just 700fps I've cleanly dropped Raccoons at 25yrd's, accuracy is a killer too. Ed

[cfxlongshot]

As my name implies I too also own a .22 cal CFX.  When I first purchased it it would only give me 535 fps with CPHP's.  I sent it to get TTuned and the velocity picked up to around 650 fps. Back then I was really chasing the FPS monster really bad and 650 fps just was not doing it.  I bought a 350mag and a refurb 460 magnum and started getting the higher velocities but when I went hunting I found that the CFX with the little 4x scope got the job done comfortably and reliably.  I found that if I don't know the fps of my gun I don't saddle it with preconceived notions of what its limitations are and I just start shooting.  You will be surprised how far a CFX can kill a rabbit or prairie dog,  I bet you find out its further than you can shoot.

[SoCalFan]

Totally agreed with your insight! I had it chronied mostly out of curiosity, plus I needed a real-world FPS to plug in when playing with Chairgun. Will start shooting for a while scopeless within 25 yards of course. Happy shooting!

[LongIslandArcher]

I tuned my .22 cal. CFX using a JM Maccari piston seal and a Theoben gas ram from AirGunWerks.com and I get 715 fps with 14.3 grain pellets.  Another CFX in .22 I have, that also has the JM Maccari piston seal and an Air Venturi gas ram gets me about 650 fps with 14.3 grain pellets.  The .22 cal. CFX is only rated at 900 fps with PBA pellets and 750 fps with (the lightest) lead pellets.

The Theoben gas ram is a lot smoother and easier to cock than the Air Venturi one, but it gets better speeds.  I speculate that it's because the Theoben gas ram body goes up into the piston, adding more mass and inertia for more efficient air compression.

[rkr]

You could also have a bad o-ring in the rotating breech. I don't remember whether it was front or rear one that, when incorrectly assembled at the factory, caused this kind of drop in velocity. Search the gamo gate for more information.