How low can you go?

[mtnGhost]

Maybe we can have a little contest and see who can tune their PCPs the lowest?! Using 18gr JSBs and not touching the reg (3.25 turns down from my 850fps tune), the Mutant shorty is apparently very happy shooting them at 220FPS @1.93FPE :0

The first shot was 212.. the rest were all 218-222

 

[vmaxpro]

Ive got a free flight hammer with a ssg thats almost endless with adjustability. I never took it below 300fps @150bar but wow what a shot count lol. Its alot of fun! 

 

[nervoustrig]

You got that tight of an ES by simply dialing down the hammer spring tension? If so, that is remarkable.

 

[ctshooter]

The Mutant and the Veteran are so easily adjusted with the hammer spring. I never took mine that low, but I do recall shooting 14.3 gr .22s at around 500fps quite easily. 

I'm gonna try this out with my Leshiy tomorrow and see how I do. Right now the reg is @130bar and I'm hittng the JSB 18.1 .22s at 950 fps with 20 clicks on the HS and 900 fps with 18 clicks, at 10 clicks they are going 670fps. Looks like I have some room there but I don't know if I'll be able to get it as low as you.

 

[Bask]

I‘m a happy new owner of the new Leshiy! Ok, new to me, because i like single shot i bought the old Leshiy . With the HAmmer spring adjust to the minimum i shoot the 34gr JSB at 280 fps. That is the .25 Leshiy.

 

[mtnGhost]

Ive got a free flight hammer with a ssg thats almost endless with adjustability. I never took it below 300fps @150bar but wow what a shot count lol. Its alot of fun!

470 shots at this power  

You got that tight of an ES by simply dialing down the hammer spring tension? If so, that is remarkable.

Yes sir. The Taipans are designed brilliantly for ease of tuning. When the regulator is set to an appropriate pressure for the projectile, the ES is as tight as the pellet weight / head diameters at nearly all velocities. They are very consistent like EDGuns.

The Mutant and the Veteran are so easily adjusted with the hammer spring. I never took mine that low, but I do recall shooting 14.3 gr .22s at around 500fps quite easily. 

I'm gonna try this out with my Leshiy tomorrow and see how I do. Right now the reg is @130bar and I'm hittng the JSB 18.1 .22s at 950 fps with 20 clicks on the HS and 900 fps with 18 clicks, at 10 clicks they are going 670fps. Looks like I have some room there but I don't know if I'll be able to get it as low as you.

130bar on my Leshiy right now (running the 250mm 22 cal barrel), 270fps with 1 click

 

[tor47]

Interesting, how does it group?

 

[nervoustrig]

Wow, that’s impressive! Do you have any idea how the hammer and valve differ from other PCPs? I’ve never seen a system that works that consistently with a light tap of the valve. The regulator pressure is still somewhat high so backing off the strike that much is basically asking it to work at a state of partial valve lock...like overfilling a conventional unregulated PCP to the point where the hammer can barely knock open the valve.

It’s the same mechanism that causes a slow first shot when a regulator creeps up after sitting idle a while, and why it’s so beneficial to get the hammer strike adjusted just right. I suspect FX would be very interested in making their design equally agnostic, what with the dozens of topics on regulator creep.

The only other concept that comes to mind is some sort of balanced valve but those tend to be even more sensitive.

 

[tor47]

If we compare with none regulated guns, shooting with high pressure , and light hammer strike is not that uncommon. So on a regulated gun, shooting at the "knee' has its advantage, but not always a must.

 

[tor47]

Also there is a limit on how low regs can be adjusted, so it is not always possible to shoot at the "knee".

 

[ctshooter]

My lowest case testing on the Leshiy:

- 18.13gr .22 (350mm barrel) on lowest setting is 390fps

- 33.95gr. 22 Jumbo Beast hit 257.5 fps - but that's kinda cheating.

I'd bet I could easily go lower if the HS adjustment let me.

 

[nervoustrig]

If we compare with none regulated guns, shooting with high pressure , and light hammer strike is not that uncommon. So on a regulated gun, shooting at the "knee' has its advantage, but not always a must.

Well okay but light is a relative term. Backing down from 850fps to 700fps is one thing. Backing down from 850fps to 200fps is quite another. That’s what has me interested because it runs counter to every experience I have with operating a PCP near valve lock. It’s not trivial to produce the infinitesimal lift and dwell necessary to bring the velocity down to 200fps _consistently_. 

We can usually see evidence of this inconsistency on the first half of the bell curve...


And the velocity swings get worse and worse the further down toward total valve lock it goes. So typically a reduction of this magnitude would be accomplished with a transfer port restrictor. It isn’t ideal because it’s somewhat wasteful of air but it keeps the ES low without having to alter the state of tune (hammer spring tension & regulator setpoint).

A hammer buffer (e.g. bstaley O-rings) helps but it has to be set up for a fairly narrow range of lift and dwell and I didn’t get the sense the OP was manipulating anything other than the hammer spring tension. I suppose it could be done in tandem with the HST and that would be pretty snazzy.

Super short dwell is fantastic in terms of efficiency and as I’m sure you know, it’s a key benefit to using a lightweight hammer. It has its limits though…using one doesn’t skirt around the erratic FPS variations that happen near valve lock. It’s a fun thing to experiment with. For example I’ve sometimes taken a 30fpe .22 down to half power for discreet suburban pest squirrel removal. Where distances are short, the mild variations in velocity aren’t meaningful, and the short dwell takes the report down to something akin to clicking an ink pen. If I could get that without the velocity swings, even better

So yeah, I’m gonna have to look into what Taipan is doing

 

[ctshooter]

Although I always love the science behind why things happen, for the purpose of this thread a few of you are overthinking a fun test. I really don't think there is any magic powder in the Veteran - the only adjustment is the hammer spring, but it is infinitely adjustable to the point it just unscrews and falls out. Maybe there is something magic going on in the valve which allows it to function consistently at such low impact force levels. 

 

[nervoustrig]

Overthinking? Okay, I can see where it comes off that way. Meanwhile you also describe it as a fun test. I think it’s more fun to a larger number of people if we understand how to get such positive results. Then we can all partake in the fun.

Every cool widget we have is something that has countless hours of thinking and effort invested in it to make it so.

 

[tor47]

Well it probably doeas not have much practical use shooting 220 fps, apart form a fun test. Few would tune a gun that low. But since the gun is capable shooting that low with stable velocity, it would probably be no problem shooting at 600-800fps range, still far lower than the max speed the reg would give.

 

[nervoustrig]

Definitely, I agree with you 100% on that.

I figured someone would at least come along and say, “Hey, why can’t my Impact do that?” but unfortunately it doesn’t seem to be generating a lot of interest. Perhaps it’s that folks are seeing 220fps and thinking, “I have no use for that” and moving on. But as I see it, the broader appeal here is:

1. Incredibly long shot count at modest velocities (say, 500 – 700fps) for backyard plinking out to 50 yards or so.
2. Insanely quiet for indoor shooting or pest removal. Really, anyone who has never tried this really owes it to themselves. It’s unreal.

 

[AirRanger]

Low power is a hoot, I often get bored of slinging lead at laser speeds and find the gentle harmonics of a properly de-tuned air rifle to be some of the most fun and challenging times you could have. That being said I recently after looking high and low found a great condition Kalibrgun Cricket Compact .177cal and it came set to 13fpe which I’m told is the lowest energy possible with this particular airgun and let me tell you what fun it is to fill that gun up with air and quietly plink targets at various distances without having to fill again for quite some time. I lost count of the shots after my 5th mag which is 70 shots with these cricket 14 shot mags. Great fun and great idea +1 to you for giving some of us something to do around the house while all this mess continues to unfold.

 

[DirtyDovi]

Neat tests and tunes!

Since I usually only shoot indoors / limited to 10m, I've done a few extreme de-tunes to my rifles before 
in order to achieve the highest amount of shot counts while still achieving descent accuracy / consistency / efficiency..
I don't remember ever getting velocities down much under 300 or 400 fps though.

I bought a Bug-A-Salt rifle to shoot flies and spiders with.. 

If I can de-tune one of my pcps down low enough, maybe I'll just use that instead?! haha

**I'm really kicking myself again for selling my Cricket Mini Carbine and Veteran**
As mentioned above, they're just so amazingly easy to adjust/tune!



Sam -

 

[mtnGhost]

Interesting, how does it group?

13 Meters with my little Burris red dot (30m zero)

 

[Glem.Chally]

Well i gave this a shot with the impact. Might try to go a bit lower.