Effect of changing barrel (.25 to .22 cal)

[ofar81]

Hi. I have an Edgun Leshiy Classic (the single shot older model... not the semi auto Leshiy 2). For those who don't know, the Leshiy classic functions like most regulated PC's. It has a regulator and a hammer spring (both adjustable). The barrel of this pcp can be easily (like in 2 minutes) exchanged. I currently have the .25 cal barrel installed and the hammer spring adjusted so that at this regulator preasure (130 bar) I'm right below the plateau with a 26 grain pellet and it is shooting at 735 fps. So my question is the following: if I simply exchange barrels (install the .22 cal instead of .25 cal), same length (250mm), and don't change anything else (don't touch the regulator or hammer spring), and if I use a pellet of the same weight (26 grain .22 cal instead it 26 grain .25 cal pellet), what would the expected velocity be? Higher, lower or the same compared to the .25 cal ? If it is higher or lower, then what would I need to do with the hammer spring to stay in the 'sweet spot' just below the plateau ( to get max speed with minimal air wasting)? Also would the expected 'sweet spot' of the .22 cal be faster or slower than that of the .25 cal?
Any info that would help me understand the effect of changing barrel calibre while keeping all other variables fixed would be much appreciated.

Thank you.

 

[EPG]

I am no expert, so this is just from sources that I’ve read…

My understanding is that larger calibers are more efficient with air use, as they provide a larger rear surface area for the compressed air to push against.

I’m not certain how that would impact your 735fps when you switch to .22… but if its true that larger calibers are more efficient, than I would expect you would need to increase hammer spring preload slightly with .22 to maintain the 735fps velocity. Its certainly easy enough to test…

 

[beerthief]

I have same gun and a .25 barrel and a .177 barrel , (bought used) shot count remains the same .177 takes more air to push the pellet . Looking for a .20 barrel now just because i want a .20 to play with .

 

[weevil]

I also have the LC in 177/350 config (currently). I suspect that you’ll see 800-810 with a direct switch to an 18 grain .22 pellet. If it is tuned on the knee, I’m sure that +/- 1 HST click will keep it close enough to not have any negative effect. I find that the knee (95%) is 4 clicks below peak speed and that 1 click increase puts it at 97% which many find acceptable. Another option, if you want to get into 850 ballpark would be to use the lighter 15.85 grain pellets.

FWIW, I run mine with Zan slugs shooting 950 on the knee and reduce the HST 5 clicks to shoot 8.6 grain pellets. Even with that suboptimal hammer (~85%), it is still pellet on pellet accuracy!

 

[barreira]

FWIW, I run mine with Zan slugs shooting 950 on the knee and reduce the HST 5 clicks to shoot 8.6 grain pellets. Even with that suboptimal hammer (~85%), it is still pellet on pellet accuracy!

In which barrel do you use the Zan slugs? Is it a Edgun barrel?

 

[Ranchibi]

Like said above, if you watch some UK 12ft/lb vids the .22 calibers get more shots than .177 at those power levels.

 

[Scouty]

Hi. I have an Edgun Leshiy Classic (the single shot older model... not the semi auto Leshiy 2). For those who don't know, the Leshiy classic functions like most regulated PC's. It has a regulator and a hammer spring (both adjustable). The barrel of this pcp can be easily (like in 2 minutes) exchanged. I currently have the .25 cal barrel installed and the hammer spring adjusted so that at this regulator preasure (130 bar) I'm right below the plateau with a 26 grain pellet and it is shooting at 735 fps. So my question is the following: if I simply exchange barrels (install the .22 cal instead of .25 cal), same length (250mm), and don't change anything else (don't touch the regulator or hammer spring), and if I use a pellet of the same weight (26 grain .22 cal instead it 26 grain .25 cal pellet), what would the expected velocity be? Higher, lower or the same compared to the .25 cal ? If it is higher or lower, then what would I need to do with the hammer spring to stay in the 'sweet spot' just below the plateau ( to get max speed with minimal air wasting)? Also would the expected 'sweet spot' of the .22 cal be faster or slower than that of the .25 cal?
Any info that would help me understand the effect of changing barrel calibre while keeping all other variables fixed would be much appreciated.

Thank you.

I have tested my Classics with 25 grain pellets in .22 & .25. With both low & moderate power setups.

I can't find the data at the moment but the .25 cal was always faster than the .22 if no other changes were made.

I am in blizzard prep mode but will look for that data & respond to your post in more detail later.

 

[Scouty]

I also have the LC in 177/350 config (currently). I suspect that you’ll see 800-810 with a direct switch to an 18 grain .22 pellet. If it is tuned on the knee, I’m sure that +/- 1 HST click will keep it close enough to not have any negative effect. I find that the knee (95%) is 4 clicks below peak speed and that 1 click increase puts it at 97% which many find acceptable. Another option, if you want to get into 850 ballpark would be to use the lighter 15.85 grain pellets.

FWIW, I run mine with Zan slugs shooting 950 on the knee and reduce the HST 5 clicks to shoot 8.6 grain pellets. Even with that suboptimal hammer (~85%), it is still pellet on pellet accuracy!

I agree. As I recall when switching barrels it was never more than one click to be in that 95% to 97% sweet spot. I believe even when switching caliber & barrel length at same time.

Likewise, I have also found the Classic to do fine with short dwell tunes. But one does have to be aware of off regulator spikes as well as slow first shots after sitting overnight. However, the latter should only happen in the case of regulator creep combined with the short dwell tune.

 

[ofar81]

I also have the LC in 177/350 config (currently). I suspect that you’ll see 800-810 with a direct switch to an 18 grain .22 pellet. If it is tuned on the knee, I’m sure that +/- 1 HST click will keep it close enough to not have any negative effect. I find that the knee (95%) is 4 clicks below peak speed and that 1 click increase puts it at 97% which many find acceptable. Another option, if you want to get into 850 ballpark would be to use the lighter 15.85 grain pellets.

FWIW, I run mine with Zan slugs shooting 950 on the knee and reduce the HST 5 clicks to shoot 8.6 grain pellets. Even with that suboptimal hammer (~85%), it is still pellet on pellet accuracy!

Thank you everyone for your replies. Weevil, you said you are shooting Zan slugs at 950 fps. What Calibre? What weight slugs? How did you get it to shoot at 950 fps?! Mine only went up to 740 fps max with the 26 grain .25 cal pellets.... (by only increasing hammer spring tension). Did you increase reg preasure? To how many bar?

 

[Scouty]

I currently have the .25 cal barrel installed and the hammer spring adjusted so that at this regulator preasure (130 bar) I'm right below the plateau with a 26 grain pellet and it is shooting at 735 fps. So my question is the following: if I simply exchange barrels (install the .22 cal instead of .25 cal), same length (250mm), and don't change anything else (don't touch the regulator or hammer spring), and if I use a pellet of the same weight (26 grain .22 cal instead it 26 grain .25 cal pellet), what would the expected velocity be? Higher, lower or the same compared to the .25 cal ?

I was only able to find some of my results on this.

In my case when shooting the .22, 25.39 grain JSBs speed was 575 FPS or 18.6 FPE. When I put in the .25/250 barrel and made no other changes I shot the 25.39 grain pellets at 633 FPS, or 22.6 FPE.

I know I tried this at lower and higher power than this but I can't seem to find those numbers. As I recall they were pretty close percentage wise.

If that is correct, you might expect a 10% decrease in speed when switching from .25 barrel to .22. So maybe around 660 FPS? If you try this please post your results.

If it is higher or lower, then what would I need to do with the hammer spring to stay in the 'sweet spot' just below the plateau ( to get max speed with minimal air wasting)?

As mentioned earlier, when my HST was set to produce 95% to 97% of the first velocity peak my recollection is that stayed the same when switching calibers. Maybe one HST click up or down but I can't find those actual results. I may have that wrong but I don't think I do.

Also would the expected 'sweet spot' of the .22 cal be faster or slower than that of the .25 cal?

Slower if using the same weight pellet, faster if going to a lighter weight .22 pellet. Where that threshold occurs, I do not know. I would guess that a Classic would shoot the .25, 20 grain H&N FTT's faster than the 18.1 grain JSBs in .22. But any weight difference greater than that and I would expect more speed from the .22. Just a guess. Maybe I'll try that if we're snowed in the next few days.

I will add that I really like my Classics in .25 regardless of power. When tuned properly they seem to have a more gentle cycle since you can achieve the same power with a lower regulator pressure and less HST.

However, there are a lot of pellet options in .22 and one can save some money if you shoot a lot. And there might be trajectory advantages with lighter pellets. It is good to have both, and even .177 if you can find one.