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New spring, disappointing results
https://www.airgunforum.ca/forums/topic67764-15.html
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Author:  GerardSamija [ Wed Apr 29, 2015 6:04 pm ]
Post subject:  Re: New spring, disappointing results

Ah, I see now, you wrote a number for 'speed of sound' and I'd been looking through that initial post for something like a time interval subtracted, since a time interval was the unit (.392 seconds) you were referring to in analyzing the recorded shot and impact sounds. Use of mixed units messed with my head, never mind. Glad to see my guesstimate of around 700fps wasn't too far wrong anyway.

Author:  Hominid [ Wed Apr 29, 2015 6:12 pm ]
Post subject:  Re: New spring, disappointing results

rsterne wrote:
Pretty speedy for a .22 cal Phantom, especially as an average over 20 yards....

Bob


That's what I thought... I measured the distance with a tape measure (60'), and entered the pellet weight... so I think I'm pretty close. With the new spring installed, it takes quite an effort to crank the barrel all the way till it catches.

Next step: find someone with a chrony somewhere in the area.

Thanks for everyone's input - you're a great bunch of guys.

Author:  DougP [ Wed Apr 29, 2015 9:04 pm ]
Post subject:  Re: New spring, disappointing results

You're only about 30 minutes away from me. I'm in Clayton. You can drop by some time and use my chrony to verify if you'd like. Just pm me and we'll arrange a time.

Author:  AceBoogie [ Thu Apr 30, 2015 1:55 am ]
Post subject:  Re: New spring, disappointing results

There is definitely two different piston lengths. If you did not replace the piston when you changed the spring there is a very good possibility that you have the longer piston length. The full power crosman quest used the shorter piston and it is compatible with the phantom. I have a pic of the two pistons. If you would like to see the difference just send me a message. Happy shoot'n
AceBoogie

Author:  Hominid [ Thu Apr 30, 2015 7:07 am ]
Post subject:  Re: New spring, disappointing results

DougP wrote:
You're only about 30 minutes away from me. I'm in Clayton. You can drop by some time and use my chrony to verify if you'd like. Just pm me and we'll arrange a time.


Right on... I'll do that!

Author:  Hominid [ Thu Apr 30, 2015 7:08 am ]
Post subject:  Re: New spring, disappointing results

AceBoogie wrote:
There is definitely two different piston lengths. If you did not replace the piston when you changed the spring there is a very good possibility that you have the longer piston length. The full power crosman quest used the shorter piston and it is compatible with the phantom. I have a pic of the two pistons. If you would like to see the difference just send me a message. Happy shoot'n
AceBoogie


Will the length affect the FPS?

Author:  rsterne [ Thu Apr 30, 2015 10:37 am ]
Post subject:  Re: New spring, disappointing results

The longer piston shortens the cocking stroke.... a LOT.... No way you are getting 740 fps with the long piston....

Bob

Author:  Huck [ Thu Apr 30, 2015 5:57 pm ]
Post subject:  Re: New spring, disappointing results

The short piston is 5-15/16" long,at least in my low power Phantom it was and it had no bleed-hole,just a puny .100 dia. wire spring.Can't say how long a long piston would be.Huck

Author:  Doc Sharptail [ Fri May 01, 2015 8:29 am ]
Post subject:  Re: New spring, disappointing results

Basic Chrony brand chronograph still retails for less than most airguns. They can be found on line for well less than 90 bucks- that's at least 30 bucks less than retail level .22 phantom. Having one will change the way you feel about modding and shooting- a lot. I can't make do without mine...

Regards,

Doc Sharptail

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