Powermax-Hipac

[Paul in MD.]

Has anyone used one of these in a 2240,looks like a good idea for hunting,and from switching back and forth from co2 to PCP.http://powermax-hipac.com/Products.aspx

[Pete]

They would have a very small volume & if unregulated
the power would drop of after a few shots very quickly..

[Paul in MD.]

30ml or 1.8 cu.in.=  about 4 or 5 good shots

[Rodents Rapture]

 That is incorrect. Shot count is determined more by the tuning of the gun relative to shooting pressure. My valve is worked and the springs are custom made. A super strong striker spring and light valve spring opens the valve easily under 3000psi. There are alot of shot-string numbers posted on the PowerMax-HiPAC Owners Forum.

The shot strings from a stock 2240 with the #1Grn spring @ 1600-2000psi are excellent. Valve-lock occurs at higher pressures requiring the heavier striker spring but the FPS average increases over fewer shots. Like I said, much of it depends on how your gun is tuned with striker spring, valve spring and shooting pressure.

 As a bulk-feed adaptor it give the shot counts and power most shooters are looking for with HPA and still allows you to go back to a CO2 pills. The best benefit is that you can fill it with a pump and air is free.

[Paul in MD.]

Rodent rapture ,That is a very nice shooter you have there ,is that a red dot, more info please .

[Rodents Rapture]

 The sight is a Simmons 4 Reticle Red Dot. It's pretty solid. I think the reticle and illumination knobs are a bit too stiff and difficult for weak hands. The wind/elev clicks are easy; very crisp and definite. The weight is about average for a RD. It's easy to zero in with 3 - 4 shots. I zero at the holey wall in my garage, -3/4" @ 20' and i'm dead on at 20yrds. Overall i'd say it's a real bargain.   

[Alan]

That's one nice rodent blastin' machine you have there.

I've never been to the dark side. . . yet.   :-)

[tworr]

I'll make this my first post.

I picked up the powermax back in May and have been doing a lot of shooting and testing different hammer spring and valve spring combination to get an idea of how they change the fps in the 2240. This is my first 2240 and it's been a learning experience for me in the workings of a PCP.

I'm still testing different valve port sizes to get an idea of the most power and consistent shots I can get using the powermax, but it's by far a better solution than using C02.


This is my best consistent group of numbers using a smaller transfer port of 5/64" instead of 11/64".

14.3 grain
2000psi
Green Hammer Spring

510.1
513.4
507.4
514.6
525.5
516.9
531.5
531.4
537.5
526.5
522.1
531.8
528.6
524.2
522.3
517.4
521.8
513.2
513.2
517.7
506.2
501.0


-----------------

14.3 grain
3000psi
Red Hammer Spring

718.7
717.7
707.6
701.4
678.3
677.5
663.0
650.8
633.9
616.5
591.6
579.9
556.9
535.9
511.8
488.1



Instead of overwhelming you with numbers you can look here http://www.network54.com/Forum/414006/message/1279304950/2240+and+powermax for some of my changes.

Up until this point I've been following everyone's valve mods and using the 11/64 transfer port hole and could never get consistent numbers. Without a bottle I think the enlarged 11/64" port mod just waste too much air. I'm going to be using a CF tank soon and will use my strongest combination to have a long shot string of 800-850fps with it.

In the meantime I've settled on a much smaller transfer port hole of 1/8" to 5/64" to get the consistent shots I've been after.

[Alan]

You've done a lot of testing, great info.  When you get the tank on there, will it be regulated?  What size tank?  I hope it works out great for you.  Will keep my eye out for updates.

Thanks, and welcome to the GTA forum.

[tworr]

Thanks!! I picked up a 68/4500 CF tank for $50 and replaced the regulator with an older style regulator that is stainless steel and rated for 4500psi. I'll post more info on it once I have it set up and working like I want or hope it will.

Here are a few more groups with different transfer ports. Which one of these or the previous one looks the best?


Stock Valve Spring
Green Hammer Spring
2000psi
5/64

462.8
470.0
469.0
468.4
468.2
470.6
477.8
475.2
477.9
477.6
478.7
482.6
484.1
483.3
482.6
481.6
482.5
474.0
476.9
476.3
475.3
468.1
465.8
463.5
455.6
453.5
451.8
440.0
438.9
426.2





Stock Valve Spring
Green Hammer Spring
2000psi
3/32

508.5
506.2
511.6
511.8
513.5
522.6
536.0
520.7
531.1
541.4
534.7
539.9
543.8
539.6
537.2
535.0
534.4
530.7
529.5
528.4
519.9
515.5
510.8
499.5
492.6
485.6
472.7
452.3
439.8


Stock Valve Spring
Green Hammer Spring
2000psi
1/8

506.1
510.3
520.6
534.5
539.9
550.8
545.4
551.7
563.0
559.1
571.4
574.0
567.6
585.0
578.5
575.8
err
575.2
568.8
559.0
549.5
538.8
523.0
507.7
488.3
470.9
448.8
428.2

Stock valve
green
1800psi
1/8

541.6
540.3
547.0
549.5
564.1
561.6
565.0
569.2
573.6
580.3
577.6
578.4
574.2
578.8
568.5
565.0
548.0
537.0
521.4
503.8
487.8
466.1
443.0
420.2

stock
green
1500psi
1/8

566.6
578.1
573.1
585.0
582.3
575.3
577.9
564.5
563.2
545.2
534.6
523.7
507.3
492.5
466.4
443.3
430.3
402.3

[Rodents Rapture]

 Nice job .You have alot more energy than I. So much taking apart and putting back together. You need a testing platform. Most of my screws wore out after 15 or 20 disassembles.

Where is the wishbone? Would love to see him around here.

[Rodents Rapture]

Just thought i'd update my shooters' photo. I cut a few more bands on the MB just in case I decided to shorten it by 1/4" at a time. The tank holds very steady under pressure and makes a good forestock if i add a plastic stock to it. I'm beginning to like the look. A stainless steel bracket for the tank,bolt and end cap will give it the final touches.

[Paul in MD.]

Tworr,Is your 2240 stock,if not what BBL. length,those # are very consistant FPS.

[tworr]

Paul, My barrel is 14.5" and I did everything from cutting a couple of threads off the cap to opening the transfer port up and using freezer tubing with 11/64" ID. I later added a delrin valve and after seeing that 11/64" was wasting air I made the transfer port smaller by using copper ground wire inside the freezer tubing and drilling 5/64" and 3/32" in it.
At the higher pressures the smaller transfer port really brought the numbers closer together. With more air from my CF tank I'll be able to use the larger transfer port
Keep in mind that I'm testing two different valve springs and the two hammer springs that came with the powermax.


Todd

[tworr]

Paul, I've changed my scope mounts to cut down on weight, but other than that this is my 2240.

[Paul in MD.]

That is a sharp looking pistol

[sshewins]

thats one fancy repeater-rotary loading clippy thing.  Where can you find one of them thar units? 

Seriously, its one nice lookin rig!

[tworr]

Thanks guys!!

A friend bought if for me from http://www.qbmags.com/page4.html

It's pretty cool, but I will say that it works better with a longer pellet. A short pellet sometimes likes to tumble out of the mag if it comes out wrong. A longer pellet lands on it's side every time and slides right in. I try to point straight down with CPs and don't have the problem I had when
i first got it.