Chronied the iguana hunter today!

Chronied the iguana hunter today!

Joined: September 7th, 2009, 10:49 pm

January 19th, 2011, 8:57 pm #1

Took some time out today and went to the shooting range to chrony the iguana hunter with the PowerMax HiPac. I used .177cal. Beeman Gold hollow points 7.2gr. and .177cal. Crosman Hunting domed 7.5gr.pellets. Charged to 1500psi/100bar used with the green spring and power adjuster backed out 3 turns.
Beeman Gold hp 7.2gr. (very erratic velocities)
#1=510fps }
#2=501fps }
#3=497fps }these were taken after the gun had been stored for 3 months(dry seals/o-rings?)
#4=478fps }
#5=481fps }

Crosman Hunting 7.5gr.
#1=531fps #6=598fps #11=583fps #16=599fps #21=591fps #26=539fps
#2=539fps #7=567fps #12=608fps #17=604fps #22=585fps #27=527fps
#3=571fps #8=589fps #13=600ps #18=595fps #23=574fps #28=524fps
#4=567fps #9=580fps #14=602fps #19=576fps #24=569fps #29=501fps
#5=564fps #10=590fps #15=599fps #20=603fps #25=563fps #30=501fps
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Joined: February 25th, 2009, 1:05 pm

January 20th, 2011, 2:19 am #2

this be enough fps to kill iguanas?
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Joined: September 7th, 2009, 10:49 pm

January 20th, 2011, 2:38 am #3

I've not modded the the valve or used other hammer springs.Gonna change the valve seal for the one that came with the HiPac which will allow me to raise the psi. Lots of variables still to play with and make it allot better.
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Joined: August 3rd, 2007, 8:13 pm

January 20th, 2011, 12:39 pm #4

Hi Tony,
I'm also trying to set up my 1740 HiPac.
My last visit to the clubs chrono produced similar results.
I'll post my string when I get home but it did have a spread of around 100fps returning up to 30 shots with a fill of 120bar.
I need to do a test like Roberts great post on how fps spread effects accuracy.
I'd like to know how to flatten the curve and open to suggestions. I could try fill pressures and have a spare hammer/striker that I can get reduced.

I live in the UK with a 6fpe max gun law. I'm looking for a maximum number of consistent 5fpe shots.
Cheers
Ian
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Joined: October 14th, 2006, 12:30 am

January 20th, 2011, 2:28 pm #5

Took some time out today and went to the shooting range to chrony the iguana hunter with the PowerMax HiPac. I used .177cal. Beeman Gold hollow points 7.2gr. and .177cal. Crosman Hunting domed 7.5gr.pellets. Charged to 1500psi/100bar used with the green spring and power adjuster backed out 3 turns.
Beeman Gold hp 7.2gr. (very erratic velocities)
#1=510fps }
#2=501fps }
#3=497fps }these were taken after the gun had been stored for 3 months(dry seals/o-rings?)
#4=478fps }
#5=481fps }

Crosman Hunting 7.5gr.
#1=531fps #6=598fps #11=583fps #16=599fps #21=591fps #26=539fps
#2=539fps #7=567fps #12=608fps #17=604fps #22=585fps #27=527fps
#3=571fps #8=589fps #13=600ps #18=595fps #23=574fps #28=524fps
#4=567fps #9=580fps #14=602fps #19=576fps #24=569fps #29=501fps
#5=564fps #10=590fps #15=599fps #20=603fps #25=563fps #30=501fps
Try the stock 22XX hammer spring. It's actually a little stiffer than the green one. I tried the red hammer spring - I'm thinking it's supposed to be used in conjunction with a power adjuster as my 22XX wouldn't even cock?





Vines



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Joined: September 7th, 2009, 10:49 pm

January 20th, 2011, 9:31 pm #6

Thanks guys for posting your experiences with the 22XX pistols and the PowerMax Hipac. This Item has allot of potential if we share our experimenting results. Still ahave allot of variables to play with.
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Joined: November 17th, 2006, 3:51 am

January 21st, 2011, 1:40 am #7

Put together a 2240 and have been working with a prototype 2260 HiPac.

there just isn't a whole lot of volume, so long shot counts aren't likely to happen at higher energy levels. Have to pretty much decide what compromise between power and shot count you are willing to live with. I personally picked 15 shots inside of 25fps variation, but your requirements can certainly be different.

I do use a lightened striker, which does seem to be more air efficent.

the strength of the striker hit to the valve sets the pressure level it runs best at (the sweet spot). Sweet spot my be short, but there are a spots where vel. stops climbing, levels off, and then falls.

Can lower the velocity and extend shot count by strangling off the transfer port (will still have about the same pressure level for the sweet spot, the vel. will just be lower).

To get those 15 shots, the 10" .177 2240 (started life as a 2300s) runs at 120BAR and 6 - 6.5 foot pounds.
[/IMG]
The 2260 gets it's 15 shots at 120bar and 17 foot pounds.
[/IMG]

Might be able to boost fill pressure, increase the striker hit, and strangle off the transfer port even more and end up at 20 good shots at about the same speed/variation... but my goal was 15 and I'll leave more experimentation until I get bored.

Have to say, the up-down-up-down tendency of your shot string isn't making tuning easy. Try a differnt pellet and see if it still gives those odd low/odd high shots. If it does, would have to look at the sear dragging the striker as a possible casue.
Last edited by gubb33ps on January 21st, 2011, 1:46 am, edited 1 time in total.
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Joined: September 7th, 2009, 10:49 pm

January 21st, 2011, 2:01 am #8

Thanks Robert for looking in on this post. I know you have been collaborating in testing Alex's new prototypes and have lots to contribute. Keep the info comin!
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Joined: November 17th, 2006, 3:51 am

January 21st, 2011, 2:50 am #9


They are basically lower pressure, small air volume, PCP's and follow the same kind of tuning steps. Have to make differnt sized transfer ports in order to stangle one off and have to either change springs or add on a "power adjuster" to change striker spring tension, but there are simple PCP's where you'd have to do the same thing in order to adjust it.

If you are comfortable running higher pressures and going for a max. effort, can get some surprising speeds/energies, but only for a very few consistent shots. Could probably strangle them down in energy and get 2 to 3X as many consistent shots per fill.
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