Chasing Backyard Friendly, low power Tuning for Backyard Pesting and Plinking

If you just want to get to the details of how/what… skip to the end ;)

The focus of this article is on tuning… not moderators, or other things you can do like opt for the longer barrel and lower hammer settings.

NOTE: If you're the type who just wants to point and shoot, and not really get into tuning... no worries.  Ed sends these things at settings that really make the gun fool proof. If however you like to tinker, and want to learn how to tune this gun.... read on.

The Leshiy has incredible power packed into a little frame.  It’s tempting to unleash that on your prey, but I’ve found that the concept of “just because you can, doesn’t mean you should” applies to airguns and pesting.  My UK friends are probably having a laugh, as they by law, are in these low power setups… but us Americans, and other countries with no power constraints, are not.

The longest shot I have is 30 yards, and I routinely shoot 15-20 for pesting.  In addition to the short range, my targets are small pests… rats and chipmunks, and in season… squirrels!  The issues I face in no particular order are Noise level, pass through, accuracy.

Initially my concentration was on noise level… so I tuned the .25 down to a speed that was the quietest I could, but still close to what I thought needed to be there power wise (30ft/lbs!).  It still wasn’t as quiet as I’d like, and thus “Silent Overkill” was born.  More on that mod here.  I now had a super quiet gun, zipping pellets through my quary and smashing into things behind it that are less than ideal (ex: very nice neighbors garage door!).  
In most cases, my “Lesihy” questions and concerns usually lead me to a call with Brian over at EdgunWest (great store btw… check it out here, and make sure to tell him his friend over at edgunleshiy.com says hello – lol).
When I presented him with my dilemma he laughed, and his response was “you know how ridiculous 30ft/lbs is for back yard, right?!?”.  He went on to tell me he shoots, and humanely (“totally destroys”) kills backyard pests.   Additionally it will give you like 40+ shots…. Wait, what?!?!... he now had my attention.

When tuning, one has 2 options, send to someone like Brian, or do it yourself.  No one knows your context for tuning needs better than yourself, so I highly recommend giving it a go.  The Leshiy is so simple… so after that initial fear, you might even enjoy working on it.

Here’s the DIY tuning process… please note: you will need a chrony, air, and some pellets ;)

NOTE: This is with the HUMA standard Leshiy regulator... the sub 12 kit is a different story.  It's the opposite concept.  Small about of air at higher pressure.

Here’s a list of products I use:

Mini Chrony Click Here
Mini Chrony Adaptor Click Here

Step 1: really define what the ideal ft/pounds you are going to target, the pellet, and then from there use this calculator to figure out the target FPS: https://www.pyramydair.com/airgun-resources/widgets/convert.php?Units&u=14

Step 2: ​In this example I'm shooting .25.  Start the reg within these ranges so you're reasonably close.

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Sub 12 ft /lb	15-20 ft/lb	20-30 ft/lb
60-75 bar	80-90 bar	105-110 bar

If you’re shooting .25 and want anything 18 ft/lbs and under, you can do the following steps, but you really need to get the Sub 12ft/lb kit.  More on that later, but you can get it here: Sub 12 Kit

While it’s not required, if you want to really dial in your tune, you can also get the reg tester.   The lines on the HUMA regs are just guides really.  This will give you the exact output:


I have not used this in my tuning, but I will probably get one to really fine tune

Step 3: fill the gun up to 20-40 bar over your reg setting.  You can do more, I'm just trying to save you some pellets

Step 4: Adjust the hammer spring to get close to your target FPS using the Chrony.

Step 5:

1. Once you’re at your optimal FPS, shoot down through a Chrony, and document each shot Bar & FPS.  
2. Keep shooting and documenting each shot well past your reg setting.
3. You’re looking for a spike… so say your target FPS was 530, as you shoot down and the pressure drops below the reg setting, you will notice a spike.  In my case I went from 530’s to 540’s and then a spike at 557.
4. Once it spikes, keep shooting until it drops back to your target FPS.  It will then fall off after that as expected.
5. That Bar where it came back off the spike is your ideal (tuned) reg setting for that target FPS determined earlier.
6. To confirm this, fill the gun up to about 10-15bar above the current (not the new one you found) reg setting, and repeat steps C-E above.  The number should be pretty close.  It won’t be exact as your fill pressure starting point won’t be the same.
7. Now you’re going to change the tune based on what you just discovered.  Degas the gun, change your reg setting, and fill back up.   I would suggest you reset your settings if you’re using the EDMU.  I’ve noticed it takes a couple times to take so you might need to do it a couple times.   Just reset the stats (how to here: EDMU Help Guide)

Note: you may need to adjust the hammer spring a click or 2 to bring back to your target FPS as well.
To know if it reset correctly, you need to shoot at least twice.  Go the AVG menu option (bullets icon with “AVG” on it). If you see “-“ or some crazy high number in the 1000’s then do the reset again.   If you have issues beyond that, the EDMU support email is awesome!  Shoot a video of whats going on (assuming you don’t speak Russian) and then send it to edmu@edgun.ru.

Shot count is an important part of a tuning process IMO.  I think it’s important though to have the gun shooting to your specific needs, and then let shot count be a result of that.  This will give you immediate feedback on the impact of the tune.

Here were my results so you can wrap your head around this and prepare for your tuning.

I’m shooting .25 cal with JSB MK2 (34gr) at a target FPS of 530 FPS.  I’m going lower BTW once my sub 12 kit arrives.


As you can see, 62 bar is the ideal setting on the reg for me to shoot 530 FPS in 34gr JSB MK 2’s in .25 cal.  Now I went and made this adjustment and saw my shot count go from 70 to 40!   The reason is because I was using the standard HUMA reg… not the sub 12.  I noted the tune, and then went back to 85 bar until my sub 12 kit arrives.  I will go through similar steps to confirm the #’s with the new reg.

Final Comments/Thoughts:
If you are shooting low power in a bigger cal (like .25), then I highly suggest getting the sub 12ft/lb kit (click here).  The gun can be tuned low, but you will have to have the hammer spring all the way backed off.  This will cause some issues… the biggest is after the gun has been sitting for awhile (overnight as an example) the first 4-8 shots will be low… causing a change in POI.   Not to get into the weeds, but at a high -level the stock hammer spring is just too big, and doesn’t allow the valve to operate correctly at such low speeds.  My suggestion is to try it with what you have, and if you love it like I did, get the sub 12ft kit.  This will not only allow you to shoot lower speeds, but will dramatically increase shot count due to the lighter hammer spring and shorter valve.