HatsanAT44 (H) Class Regulator

I installed two of these regulators in my two cylinders for my Hatsan Bullboss .25. I was able to adjust both so that they were within 4 fps of each other on average. Shooting 33.95 grain JSB King Heavy pellets, one cylinder averages 767 fps and the other 763 fps. I get 18 quality shots from each cylinder. Spread within the 18 shots is 23 fps for both cylinders. Now to move on to lighter pellets to see what kind of results I get there. So far, I'm pleased.

Works well, must have for AT44.

Upon inspection of this package (opened box w/missing o-ring seal) I realized that this unit was not at factory setting.Took me some time to build a testing unit to re-set the output pressure.Either way I did finally manage to get it to work as I had wanted.This unit was designed for the newer valve system with threads, and not fit any of the older delrin snap on type.Be Aware of which valve spring retainer you have in your PCP before ordering. Grab one if you are able to machine the parts needed to make it work for you.

Awesome product

This regulator did not fit in a Hatsan Bullboss. Maybe they send me the wrong one,because the item that I received looks different than the one in the picture. It looks very similar but did not have O-ring. I tried to screwed the regulator in but the thread did not fit also. I had to return it back to Amazon.