WOW. I have entered the black hole of Hatsan tuning. lol. I swapped the outlet valve spring inside the brass cap that one slots a V-groove into when a HUMA is installed...
I left the HUMA set at 130 bar. I did take a few shots that were all over the place. Realllly low speeds, but I had left the hammer spring all the way relaxed. 450fps, then 570 to 670. I did some increased tension hammer turns and some more turns...
Nothing wild but went from 768's with stock spring to 788's with this new spring. I have run out of 25 gr ammo until I relocate where I put my other tin. But my shots that registered over the chrony were no LOWER than 780. And ya know what, this is good data. I will take a photo of the spring I swapped it for but it was a perfect fit, just not as heavy tension.
I read online that in essence the HUMA or any regulator can radically change the factory tune of a non-regulated rifle. We all know this basically...usually the hammer spring needs to be lighter as the air volume is less in the plenum. BUT with this Hatsan's heavy spring it was not letting (I guess) the air escape efficiently...
So by me reducing the resistance of what the hammer face comes against it changed that, clearly. Same rifle, same settings, same ammo, same starting pressure (200 BAR). I hope to mess with it more tomorrow.
This is the factory spring I replaced for this test. Rifle when from being 32/33 ft/lb to mid 34 ft lb...and regulator is still at just 130 BAR. If I go to 150 or max of 170 it then that will be data I'd be happy to see.
I left the HUMA set at 130 bar. I did take a few shots that were all over the place. Realllly low speeds, but I had left the hammer spring all the way relaxed. 450fps, then 570 to 670. I did some increased tension hammer turns and some more turns...
Nothing wild but went from 768's with stock spring to 788's with this new spring. I have run out of 25 gr ammo until I relocate where I put my other tin. But my shots that registered over the chrony were no LOWER than 780. And ya know what, this is good data. I will take a photo of the spring I swapped it for but it was a perfect fit, just not as heavy tension.
I read online that in essence the HUMA or any regulator can radically change the factory tune of a non-regulated rifle. We all know this basically...usually the hammer spring needs to be lighter as the air volume is less in the plenum. BUT with this Hatsan's heavy spring it was not letting (I guess) the air escape efficiently...
So by me reducing the resistance of what the hammer face comes against it changed that, clearly. Same rifle, same settings, same ammo, same starting pressure (200 BAR). I hope to mess with it more tomorrow.
This is the factory spring I replaced for this test. Rifle when from being 32/33 ft/lb to mid 34 ft lb...and regulator is still at just 130 BAR. If I go to 150 or max of 170 it then that will be data I'd be happy to see.
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