Hammer spring adjustment
My cricket is shooting at 940 FPS with 25.6 Exacts, my question is, how much could i expect to slow it down via the HST adjustment? Also, is this a good idea? I would like to get down around 900 FPS for more shot count and maybe a bit quieter. The reason i ask about the HST adjuster is because I have read about keeping the regulator and HS in scyned, pretty sure i misspelled that. I am sure someone can set me straight. Thanks in advance.
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Exactly ! If it shoots at a steady speed then why bother.
If it doesn’t then it’s time to dive into things.
Sounds easy enough. I’ve shot it down around 930 yesterday in almost ideal conditions for outside and grouped a little better at 100yds than it did at 980-990. I couldn’t tell that much difference at 60 though. Sucks when a gun shoots that good and clouds results. I think if you can shoot more longer range it tells the tale. I ain’t jack’n with nothing as well as its shooting now, though, well maybe a mild barrel polishing.
Jk
Just back it off so it doesn´t have all too much tension when you start. A couple of turns in from the start. Once you get into trial/error and try to find the needed reg pressure you just back the HS out a turn or two (preferably two) from the setting you came at the last time. Confusing ??
Sir Ville, using this method, how much preload do you have on the HS? Is the adjuster turned in just enough to engage the threads and not fly out or do you have 4-5 turns CW. It sounds like where ever your start with the HS setting your adjusting the regulator to sinc them together :confusedn: :confusedn: :confusedn:
JK
NO positive stop on the factory HST.
120 bar seems low enough to get below 900 fps using JSB Kings ?
Try Ernest’s procedure above maybe your HST is set to low. Start it where it was before adjustments.
Sometimes going in CW on the HST will result in a lower speed !
~ GKU
Happy Thanksgiving everyone.
jk
Where is your regulator set at ?
It must be hi to shoot Kings at 990 ?
At 940 is your HST all the way out CCW already ?
~ GKU
It fell off the regulator at 120ish. As far as the position of the adjuster, at 990 is was beyond flush with the back of the reciever about 1/16″. Now it’s closer to flush, not very precise I know. I do remember it took two CCW turns to get it down to 940’s. Does the HS adjuster come out at full CCW or does it have a positive stop? It would be nice if it was positive for counting revolutions CW. Seems like there wasn’t a stop in a video I watched.
Jk
more info for the 25 cal Cricket,
All depend what target speed you want. around 950fps shooting king.
1.valve stem spring 1/2 turn.
2. reg pressure 135 to 140B
3. HST set at the highest speed.(bottoming out the HST adjuster will not give you the highest speed, most of the time it will lower the speed)
~ GKU
Happy Thanksgiving everyone.
jk
Where is your regulator set at ?
It must be hi to shoot Kings at 990 ?
At 940 is your HST all the way out CCW already ?
~ GKU
I guess Ernest’s procedure would be the same for the 25? Does it matter where the HS is set when you start. I shot a couple through the chrony after cleaning today and it’s right at 960. I guess his procedure would tell me something even where it is set now. As far as I know the gun was never tweaked before I got it and it was shooting an average of 990. :suprisedn: I should have some time tomorrow to test his procedure.
Happy Thanksgiving everyone.
jk
I love my Compact .177 cal it’s a real pleasure to shoot her. Like Sir Ville said it is LASER accurate ! It’ needs a firmer hold to keep the muzzle down when shooting compared to my .22 STD. It seems to like JSB everything so far Heavies and Monsters are it’s favorite. CPH brown box are good enough for back yard plinking. It’s HST is tune to send JSB 10.34 gr @ 890ish filled to 210 bar ending at 110 bar with a 6 mags = 84 shot string.
Still very new @ 1,000 shots, weighting in at 6 lbs, 4 oz. as seen.
~ GKU, hey guys have a Wonderful Turkey Day !!!!!!!!!!! 
It´s a laser at indoor range / without wind outside. It will do 14 shot groups (one mag) inside 20mm radius at 50 meters. At up to 35 meters it´s really a one hole affair – even with some wind. By one hole i mean one, little hole that looks like 4-5 shots although it´s a full mag.
The funniest Airgun i´ve ever had and it will never leave my collection. Powerful enough for Crows and Doves at 65 meters and they drop like a wet sock.
I will test both 13 & 16 gr JSB´s when i get time. I´d like it to shoot the 13 grainers at 280 mps/920´ísh so i need to fiddle with the adjustements again. 16 grainers at 270 mps wouldn´t be too bad either.
I have my .177 Compact set so the reg is set at 107-108 B (with a reg setter), the valve spring tension at 1 turn and that gives me very steady 930 fps with JSB Heavy 10.34 gr pellets. If i want to go far down in power i need to change for shorter or , better yet , weaker hammer spring.
Ville can you tell me how accurate your compact .177 is at 50 yards with the JSB 10.34 gr pellets
There it was well explained ! I use the HST adjuster for fine tuning and before i´m at where i want to be i use it as a “guide/tool” so i can find the correct reg pressure.
I have my .177 Compact set so the reg is set at 107-108 B (with a reg setter), the valve spring tension at 1 turn and that gives me very steady 930 fps with JSB Heavy 10.34 gr pellets. If i want to go far down in power i need to change for shorter or , better yet , weaker hammer spring.
I notice I’m not able to tune up higher then 890ish with JSB 18 gr my reg is set to 125 bar on my 22 cal, but I’m able to tune down more easily.
FYI from Ernest,
“Most new cricket are over adjusted, to get more shots without going in and adjusting the reg and valve stem spring:
1. got to have a crony!
2. shoot 3 shot and record speed
3. turn HST one full turn CW
4. shot 3 shots
5. record speed, did it go up? if yes, continue turning HST 1/4″ turn at a time till speed no longer rise.
6. if your speed exceed over 910fps your reg pressure is set to high if you want to shoot around 880fps to get the most shot count.
all cricket are not the same so you reading may vary–but close.
7. if your speed doesn’t go up at all in step 2, turn HST 1/4 turn CCW.
8. take 5 shots, if speed doesn’t go down turn another 1/4 turn CCW take 5 shots, continue adjusting till your speed drop 5 to 8fps.
with this setting you will get more shots.
To get the most shot count at 880fps: valve stem spring retainer 1/2 turn, reg at 115-120B, HST set at the highest FPS–hopefully around 870-880fps.
Ernest”
It was better for me to start on the hi side and tune down on the HST then starting out low and tune up. The efficiency turn out some what better that way. Filled to 210 bar down to 130 bar 56 shots, 1.43 bar per shot efficiency. Not to brag or anything but for your reference and seen that some are getting lower values.
~ GKU
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Crack Smacker, those groups you showed me sure look good at 100 yards. Why change anything. If it ain’t broke don’t fix it!