Advice needed! 22cal Hatsun bullboss added a regulator was supposed to be set at 145bar from Huma. Installed it and it seems to be working properly for consistent speed 25.39 JSB at 750FPS! I wanted to be in the high 800 close to 900FPS! I got the big plenum Huma regulator! I'm wondering if they set it 145bar! Before it was shooting a lot faster I haven't touched the hammer spring! Not any good directions on how to do so, not even in the manual! Watched some videos but haven't found a good one on the bullboss!
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Hatsun bullboss help
- Thread starter Eric1967
- Start date
Did you double check the regulator before you put it in? There is a small mark on the brass as an indicator. I would remove it and double check to make sure it is set where you want it. Also triple check the installation instructions for proper alignment and depth of the regulator. Lastly I would make sure none of the orings were damaged during the install. IF all this checks out I would try adjusting the hammer spring to see if that has any effect on your velocities.
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I would say you def need to adjust the hammer spring going from an un-regulated gun to a regulated one. Not a big deal really. Let us know how you make out!
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To adjust the hammer spring tension you will need a long 4 mm Allen wrench and something to stick through the hammer to keep it from turning. There is a hole through the hammer you will need to line it up by turning the hammer with the Allen wrench. On mine i need to have the cocking lever out but not cocked to get it to line up once this is done you can adjust by turning counter clockwise to increase power or clockwise to decrease power 
i when i have my Huma regulator set at 145 bar it shoots the redesigned monsters at 880 fps my bullboss has a modified valve and transfer port.
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Over the road trucker it will take several days to get back to you on modifications! But the hole behind the lever is that the one you use to secure hammer?
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Also no leaks and it's very consistent 5 times in a row I hit 747FPS! I JUST WANT MORE POWER FOR HUNTING!
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Over the road trucker it will take several days to get back to you on modifications! But the hole behind the lever is that the one you use to secure hammer? Ok I see pic great I'll check hammer first then work on regulator if that dont fix it!
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What caliber? What pellet? I guessing .25 the valve port is to small. The white seat of the valve can be drill out to up your speed. The gun should have came with a extra. I want to say it need to be drill out to .187
Your regulator is to high.
Your regulator is to high.
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I installed a .22 huma in a gladius. I was shooting 21 at 900 (or something) Barracuda but after the reg installed, I had to move down to jsb 18 to get appropriate speed. You should get some speed up with the hammer spring, but dont believe in miracles. It a small plenum. An unregulated gun has a ton of power, regulated ones with after market regs dont. My gladius went from like 32 ft/lbs to 26ft/lbs. It was very accurate with the reg. although and got more shots.
To get a regulated gun that can shoot 25grain redesigneds at 950, takes big bucks. Believe me I too tried moding a $500 but it never really worked. I ended up buying a $1800 one and still had to tweaking it out to get 25 gains Redigneds to fly right.
To get a regulated gun that can shoot 25grain redesigneds at 950, takes big bucks. Believe me I too tried moding a $500 but it never really worked. I ended up buying a $1800 one and still had to tweaking it out to get 25 gains Redigneds to fly right.
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Try hammer spring, loosen the valve return spring. What CC is the XXL Plenum? Not aware of it.
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It's a .22, 25gr redesigns, you want 900fpps with a 23" barrel. Your valve is not letting enuff air through. Like Davidsng said it take a big buck. IMHO that gun will not push the 25gr pellet at 900fps with out a ton of mods. Your trying to build 45 fpe with a short barrel and small transfer port. The 700mm barrels (27.5") have a hard time pushing the 25gr .22
If I'm not mistaken the transfer port on that gun is .185 thats barely.80% of the .22. But thats not your biggest limiting factor. The valve seat is. The hole is is around a .170 and has a valve stem of .100. Leaving you limited air flow.
If I'm not mistaken the transfer port on that gun is .185 thats barely.80% of the .22. But thats not your biggest limiting factor. The valve seat is. The hole is is around a .170 and has a valve stem of .100. Leaving you limited air flow.
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