 |  | | | |  | |  |  | 46 FPE Disco |  | |  |  | |
 Posted: Fri Sep 04, 2009 11:00 am |
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| rsterne |
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| Location: Coalmont, BC |
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I'm still playing with improvements on my Discovery.... I think this is pretty much the end of the line without exceeding the 2400 psi "yellow zone" on the gauge.... To achieve these results, I drilled out the transfer and barrel ports, bored out the valve and streamlined the exhaust port, shortened the stem slightly, and installed a stronger hammer spring with adjuster.... I cranked the adjuster to coil bind and backed it off 1/4 turn so that it would cock safely.... All the light to medium weight pellets I tested had their highest velocity on the first shot, and had dropped to 96% of that value by shots 6 to 8.... indicating that with these pellets, the hammer spring setting is too high for 2400 psi.... The only pellet that delivered a "normal" shot string was EunJin Domed 28.7 gr....
842
846
850
854
850
856
858
857
852
841
838
833
By the 12th shot, the pressure had dropped to 1700 psi.... but the average was 848 fps = 46 FPE.... and only a 3% variation in velocity across the string....   
My stock Disco ran 21-23 FPE depending on pellets, so I have DOUBLED the power with relatively minor and inexpensive changes (providing you can do the work yourself)....
My work now will be returning to lengthening and flattening the shot string and hopefully coming up with a combination that will allow at least a couple of different setups for hunting and plinking with just tweaking the adjuster and maybe a pellet change.... 
Bob |
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Dominion Marksman Silver Shield - 5890 x 6000 in 1976, and downhill ever since!
Airsonal: Too many to count! |
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| Posted: Fri Sep 04, 2009 2:48 pm |
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| AirGunEric |
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| Could you not let off (with the adjuster) on the hammer spring tension to allow for greater consistency with lighter pellets? Or were the modifications so extensive the hammer adjustment couldn't deal with it? |
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| Posted: Fri Sep 04, 2009 4:40 pm |
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| kanyon |
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| Joined: 09 Aug 2008 |
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| Location: New Zealand |
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Thats pretty kool for a old disco....
Its about the same out put as a Career Infinity..
Pete |
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| Posted: Fri Sep 04, 2009 4:48 pm |
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| rsterne |
| Moderator |
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| Joined: 15 Jan 2008 |
| Posts: 2998 |
| Location: Coalmont, BC |
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Absolutely you can reduce hammer spring tension for lighter pellets.... In this trial I was just "goin' for broke"....
I'll be posting more in the Disco Shot String thread when I'm finished my testing on this hammer spring....
Bob |
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Dominion Marksman Silver Shield - 5890 x 6000 in 1976, and downhill ever since!
Airsonal: Too many to count! |
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| | | | | | | | | 46 FPE Disco | | | | | |
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