Adjustable PCP’s? Are they accurate shooting High or Low ft./s? My PCP’s are!

[JoeKool]

Hello AirgunNation Peoples,



All these wonderful adjustable PCP’s on the market today huh? I mean with one PCP you could have a sub-12ft. pounder up to a you name it power level!! But... Are they accurate at the different tunable powers?



I think that’s a great test to run!


I’m gonna take three of my adjustable PCP’s and shoot them for groups at “ideal” and “power” velocities. How about 50 and 75 yards for the test ranges? Why not? And, I’ll use each PCP’s favorite heavy diabolo pellet..



Let’s Go!!!


The PCP’s and the Heavy Diabolo pellets

About the PCP’s

Ideal Speed Tune (.25/.30 & “MIN” HST)

Power Tune (.25/.30 & “4” HST)

Ideal Speed Tune. (HST #3)

Power Tune (HST #7)

Ideal Speed Tune (.177/.22 & “4” HST)

Power tune (.25/.30 & “MAX” HST)

The range, the wind, and the shooting 

Scope-view (Dreamline-Bullpup .22 Hawke Sidewinder 16x zoom 75yards)

Targets, target close ups, and group breakdowns



50 yards (left to right: Crown, Dreamline, Wildcat)

75 yards (left to right: Crown, Dreamline, Wildcat)

Dreamline Bullpup .22

Accuracy on Ideal tune or Power tune

Accuracy on Ideal tune or Power tune




Wildcat MKIII .25

Accuracy on Ideal tune or Power tune

Accuracy on Ideal tune or Power tune. Here on the lower group @ 960 fps I botched one shot high because I forgot my hold over. I mistakenly held 1.5 mils when the holdover was only 1 mil. Messed up what was going to be a fine group, sucks when that happens! (1.5 mils is the holdover for the 860 fps tune)





Crown .25

Accuracy on Ideal or Power tune

Accuracy on Ideal or Power tune. For the FX Crown, it was one of those not the greatest 75 yard group days. It’s done though and I have shot better groups with it, even @ 100 yards. Not the greatest or tightest groups, but they are honest. Even still, both groups are comparable in size!



Conclusion



Looks like these three power adjustable PCP’s do alright shooting at regular ideal velocities or powered up! Admittedly, I’ve done some upgrades, but only to beef up their speed and energy output for my uses. So, I suppose the external adjustability of these PCP’s are more than a gimmick. Because fair repeatable accuracy was achievable at respectable airgun distances. My question is; “How does your PCP perform on it’s variable power settings”?





JoeKool

 

[Yo]

IDK I have multiple guns in the same calibers and just set them once and forget it. Just bought another Impact with slug liner just to shoot Corbin NSA slugs at 930fps at 200 yards MOA. Didn't want to mess up my other perfect tuned pellet shooting Impact for shorter 100 yard distance.

 

[JungleShooter]

Well, Joe,

to me those look like some very encouraging results! Thank you. Seems like adjusting power is a viable option, not just a gimmick. Sure, for competitions there's probably an ideal setting, but hunting... — all good.

Matthias

 

[JoeKool]

IDK I have multiple guns in the same calibers and just set them once and forget it. Just bought another Impact with slug liner just to shoot Corbin NSA slugs at 930fps at 200 yards MOA. Didn't want to mess up my other perfect tuned pellet shooting Impact for shorter 100 yard distance.

You sir, are the King !

And

All should bow to your feet! 

 

[Franklink]

Very cool experiment. Lots of time and effort to perform and document the testing so thoroughly. Thank you.

A friend and I got after some pdogs this past Saturday. He tuned his Safari down to about 32fpe with the JSB 18.13s, partially for safety and partially to increase shot count. The furthest connecting shot was at 174yards and I was completely stoked to see it. Many more 150+ yard dead dogs made by him and that rig. 

I was using my Veteran Shorty at about 27.5fpe, also with the JSB 18.1, and my furthest kill was 144 yds. I usually have that little Shorty at 20fpe but it seems to shoot equally accurately at either power level. 

Similar to your experiment (but less supporting data) his Safari did really well at a power level less than its max. And my Vet was no slouch at a different fpe than I normally run it. 

Fun stuff. 

(Really surprised to see how much success we had at such relatively long, for pellets, ranges. Even our misses were only off by small amounts, with dust flying right at their feet or pellets whizzing past them within an inch or so. A perfect example of how sometimes less is more). 

 

[Long_Gun_Dallas]

My 380mm barreled 22 Crown is regularly shot at ~680fps (jsb 18.13) and 960fps (hades). Without touching the regulator. Just twist the port knob and hammer to full bore. Or bare minimum. Both speeds are pinpoint accurate.

Your speeds dont seem all that far apart. But still a good test and even better documentation as always. Thanks for sharing

 

[JoeKool]

IDK I have multiple guns in the same calibers and just set them once and forget it. Just bought another Impact with slug liner just to shoot Corbin NSA slugs at 930fps at 200 yards MOA. Didn't want to mess up my other perfect tuned pellet shooting Impact for shorter 100 yard distance.

News to me... What’s Corbin NSA slugs? Talk to me Yo?? Inquiring mind.

 

[Yo]

I bought the same dies manufactured by Corbin that NSA uses to make their slugs. Personal use only not for resale or donation!!!

It was The ability to fine tune the weight and length and flat base or curved base essentially home brew any size and weight even in between NSAs commercially available ones that sold me. Plus I have been talking story with someone who already had MOA success at 200 yards based on trial and error.

You can manufacture your own slugs that can be changed to shoot better in your slug shooters. (OR NOT!)

I have already had great success with 25 caliber Pellet Swage dies from another but questionable source and had first hand sub half MOA at 100 yards shooting them in several different brands of guns. Why do you think Air Hunters SA get unrealistic long range hits shooting pellets while most normal airgunners can't? They don't have the magical dies to make their own perfect pellets to shoot. I won't promote it because of the genuine risk of paying $1100-$1200 then never receiving them due to customs from the sellers side. It is not the seller's fault and is not expected to do any refund since its out of his control. I sell await another set of dies but worry these may have gotten confiscated.

 

[JoeKool]

Very cool experiment. Lots of time and effort to perform and document the testing so thoroughly. Thank you.

A friend and I got after some pdogs this past Saturday. He tuned his Safari down to about 32fpe with the JSB 18.13s, partially for safety and partially to increase shot count. The furthest connecting shot was at 174yards and I was completely stoked to see it. Many more 150+ yard dead dogs made by him and that rig. 

I was using my Veteran Shorty at about 27.5fpe, also with the JSB 18.1, and my furthest kill was 144 yds. I usually have that little Shorty at 20fpe but it seems to shoot equally accurately at either power level. 

Similar to your experiment (but less supporting data) his Safari did really well at a power level less than its max. And my Vet was no slouch at a different fpe than I normally run it. 

Fun stuff. 

(Really surprised to see how much success we had at such relatively long, for pellets, ranges. Even our misses were only off by small amounts, with dust flying right at their feet or pellets whizzing past them within an inch or so. A perfect example of how sometimes less is more).

Sounds pretty darn amazing, good stuff!!

My 380mm barreled 22 Crown is regularly shot at ~680fps (jsb 18.13) and 960fps (hades). Without touching the regulator. Just twist the port knob and hammer to full bore. Or bare minimum. Both speeds are pinpoint accurate.

Your speeds dont seem all that far apart. But still a good test and even better documentation as always. Thanks for sharing

Wish I that I could magically turn my Crown in to a Crown Continuum , with the SuperLite barrels and the Pic-rails on the breech block! But, I guess I still like my old Gen-2 girl.


These external adjustments are the bees-knees bro! Sounds like you’re getting killer performance! Granted my speeds don’t represent true low power or velocities but for me, those are my lows. Hat’s off to all air-gunners shooting below 700 ft./s, but it’s just not my bag.. I’m sorry .

 

[JoeKool]

I bought the same dies manufactured by Corbin that NSA uses to make their slugs. Personal use only not for resale or donation!!!

It was The ability to fine tune the weight and length and flat base or curved base essentially home brew any size and weight even in between NSAs commercially available ones that sold me. Plus I have been talking story with someone who already had MOA success at 200 yards based on trial and error.

You can manufacture your own slugs that can be changed to shoot better in your slug shooters. (OR NOT!)

I have already had great success with 25 caliber Pellet Swage dies from another but questionable source and had first hand sub half MOA at 100 yards shooting them in several different brands of guns. Why do you think Air Hunters SA get unrealistic long range hits shooting pellets while most normal airgunners can't? They don't have the magical dies to make their own perfect pellets to shoot. I won't promote it because of the genuine risk of paying $1100-$1200 then never receiving them due to customs from the sellers side. It is not the seller's fault and is not expected to do any refund since its out of his control. I sell await another set of dies but worry these may have gotten confiscated.

That’s intensely insane stuff!! In a good way!



Corbin NSA’s...



Real BADA$$ YO!!

 

[Long_Gun_Dallas]

Joe, I can't recall who, but one of the Crown owners I spoke with harassed FX enough to get a new PIC block off of them, lol. I can take or leave the 11mm or 20mm rail, as long as I have one! Haha. Yours looks like a real shooter though. I can't say I'd change a thing about it.



Also, sub 700fps is just about the perfect speed you can get a soda can to actually catch the 18gr pellet if you hit it just right. Pretty satisfying crunch  I also hunt a lot of woods, so most shots are pretty short, and 15FPE is flat out plenty of punch. Also sooo much quieter than running the gun wide open.

 

[JoeKool]

Joe, I can't recall who, but one of the Crown owners I spoke with harassed FX enough to get a new PIC block off of them, lol. I can take or leave the 11mm or 20mm rail, as long as I have one! Haha. Yours looks like a real shooter though. I can't say I'd change a thing about it.



Also, sub 700fps is just about the perfect speed you can get a soda can to actually catch the 18gr pellet if you hit it just right. Pretty satisfying crunch 

I also hunt a lot of woods, so most shots are pretty short, and 15FPE is flat out plenty of punch. Also sooo much quieter than running the gun wide open.

Yeah, that was a wish that sort of faded. I more felt that way when the Continuum was first released, now its not really a thing. I love my Crown, its my top gun!


No doubt low power can get it done. My .177 AA Pro-Sport Walnut has more squirrels under its belt than any of my PCP’s and it’s @ 16 fpe. But it launches JSB 10.34’s @ 845 ft./s.



Many game critters shot but ran or flew off stories I could tell, but I’ll just keep it at they’re not my thing. Kind of like PCP pistols.. Not interested.. But, have many many uses, probably have more precision, and can be great fun! No doubt about it.

 

[Bigragu]

Once again, another great write up. Gotta hand it to you, KoolJoe, that your personal and shared experiments have unveiled a lot of mystery’s regarding point of impact tests with adjustable pcp’s.

thank you

 

[buckyusn]

Great write up! Thank you for all of the work it took to produce this. I will have to see what my .22 Avenger can do with low & high power tunes for comparison.

Cheers,

Bill

 

[JamesD.]

I'm impressed with your post and notations in the pictures.

I'm not a tech/computer savvy person so no idea how to do what you did, but; great post.

I'm now going to set up & try to do some groups with my best JSB 18.13 spitter. I'll be using a tethered step down in-line reg. 
The rifle has a newly rebuilt reg set at 140. A bit high but it's an FX Elite & I can swap barrels in under 40 seconds. So it can send the 33.95's in .25 also.

I just have everything perfect for the .22 that's on it as of now. Don't want to reset everything other than put the dummy reg body in.

 

[Feinwerk]

Hello all,

In my experience with the .22 FX Independence, which has 3 power settings in its dial wheel transfer port restrictor mechanism, I needed to evaluate and select a 'best pellet' independently for each power level (pun intended LOL). The flight and stabilization characteristics will change with large variations in velocity.

If I'm not mistaken, the FX Independence receiver mechanism is the same as the FX Royale 400, and my results may apply to those and similar designs as well.

I maxed out the hammer spring in mine and left it fixed. The next variable was to choose a consistent target plenum pressure to pump to for each shot; analogous to setting the regulator pressure in a regulated gun. With the pump onboard, you become the regulator by pumping after each shot for consistent plenum pressures. I have been using 220 BAR/3200 psi. Yes I know, that's high! After some testing, you quickly learn how many pumps to use after the shot for each of the 3 power levels to return the plenum pressure back to your desired target level.

But something very good happens in this gun with high plenum pressure and restricted transfer port at the lower power settings: the report gets very quiet while still maintaining good velocities. I think it's more efficient with air as well.

See the attached photo of my trajectory table/range card, with separated sections for each of the three power wheel settings. There are many variations possible, so you have to just FIX some variables/settings, and roll with the rest. I don't like to keep disturbing the hammer spring tension, for instance. 

So finally, we get to my point: the most accurate pellet at low & medium is the JSB 14.3gr, while others are better on high.

I do most of my shooting on medium, where the JSB 14.3 @ 805 FPS is extremely effective on skverls, gives a zero crossing at 20 & 30 yd ( my most common ranges), the report is VERY discrete, and only 3 pumps are required to recharge for each shot.

Low power at 635 FPS, is super duper for all day plinking, with just 1 pump required to recharge for each shot. All I need for all day PCP fun are the gun, pellets, fun targets, and the air that I breathe.

High power, btw, requires 5 pumps per shot to recharge, and I found it to be no more effective on skverls at my short distances.

Since 2014 when I developed this tuning for the Independence, I have learned that diabolo pellets tend to have a sweet spot for accuracy around 875ish FPS. If I ever decide to revisit the tuning for this gun, I think I would start by dialing the hammer spring back to deliver 875 FPS on high and evaluate pellets all over again at each power level. This is a LOT of work, with all new range tables and hold points. This would also detune the medium and low settings, making then slower. Re-experimenting with variations of target plenum pressure opens a whole new series of tests and possibilities, again analogous to finding the optimum regulator pressure for each power level. Swirly-head, here I come!

I really like the FX Independence. It had to go back for service in the first year to get the new stainless pump tube parts (essentially a silent recall), but since then it has been reliable. I believe I can learn to disassemble and rebuild it myself if necessary. I've had the receiver apart once to polish the valve stem (DO NOT DRY FIRE IT when nearly out of pressure!!!) and found lots of silicone gunk inside the plenum, adjacent to the Foster fill port (which I never use).

Longish post, but hopefully my description supports the notion of exploring PCPs at their various power levels.

Good luck and have fun with your stuff!

Feinwerk

 

[jgburks]

Incredible post! Love my DreamPup and shoot it sub 12-FP in the backyard most of the time, but love the ability to crank it up at longer ranges.

One question - how low does your Wildcat go with just the HST adjustment? I've wondered if it will go as low as the DreamPup.

Thanks for taking the time to put this together and share it!

 

[Feinwerk]

For those who've never seen one, here's a pic of my Independence when it was new in 2014, with the pump arm partially opened. Also a shot of the left side of the receiver, showing the transfer port power adjuster wheel ( "." ".." & "..." Markings). You can also see the markings stating max pressure rating of 220 BAR.

I have since printed and laminated my range table and taped it to the left side of the buttstock for quick reference.

 

[Feinwerk]

Whoops, that is an old trajectory table.... I have a newer one that's more fully populated with holdover data that I can post after I rephotograph it. But the format is useful as an example of one way to organize shooting data for multiple speeds and pellets.

Feinwerk

 

[JoeKool]

Once again, another great write up. Gotta hand it to you, KoolJoe, that your personal and shared experiments have unveiled a lot of mystery’s regarding point of impact tests with adjustable pcp’s.

thank you

I’m always shooting and goofing off. Now and again I’ll take some pictures and come up with a way to tell you guys the story! Lol.. It’s fun!


You’re welcome 



KoolJoe

Great write up! Thank you for all of the work it took to produce this. I will have to see what my .22 Avenger can do with low & high power tunes for comparison.

Cheers,

Bill

Awesome, let’s see it Bill!

Thanks

I'm impressed with your post and notations in the pictures.

I'm not a tech/computer savvy person so no idea how to do what you did, but; great post.

I'm now going to set up & try to do some groups with my best JSB 18.13 spitter. I'll be using a tethered step down in-line reg. 
The rifle has a newly rebuilt reg set at 140. A bit high but it's an FX Elite & I can swap barrels in under 40 seconds. So it can send the 33.95's in .25 also.

I just have everything perfect for the .22 that's on it as of now. Don't want to reset everything other than put the dummy reg body in.

Well, I’m way too ugly to make YouTube videos, so this is my outlet! Lol!!! Kidding..



I’m a set it and forget it guy also. Once done with my modifications and tuning my guns remain right where I set them up at. For different projectiles I may turn and click some external knobs, but I’m not pulling liners and tearing down the gun & yada yada much any longer. FX Elite... Classic! I wouldn’t want you to jack with or jack up your nice airgun just to show us it’s capability. I believe you, leave that baby where she is!?