Hatsan AT44 (H) Class Regulator, One Size, Black

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.

Awesome product

This product is absolute crap. Buy a huma regulator.

First the GOOD:+Price...+ The regulator made my crappy .177 Bullboss useable! Before the regulator, after a fill, my Bullboss would have 4 supersonic shots, then a good group, then the rest were useless non grouping shots.+++ Now with the factory regulator setting, the Bullboss 177 will do two 10.6gr pellet magazines in the +/- 930fps range with reasonable groups.The BAD:- No instructions and the Hatsan online information is for a different designs. The one I received, doesn't have a second "o" ring like the online Hatsan PDF.- The video online is also for a different design valve.- In addition, with the one I received, if I followed the Hatsan installation PDF and removed the valve main tube "o" ring it wouldn't have functional at all.Bottomline, if you are some who is cheap and likes to tinker then buy this and take your chances you can make it work on your gunBut, if want instructions, and accurate how to YouTube videos. Buy one of a more expensive regulators and a better gun than the too heavy, clunky Hatsan Bullboss.

I have 3 of these regulators. This one was the last one I purchased. My gun seemed to run out of breath after the first shot. It was like the plenum could not fill. I ended up returning this one, Out of my other 2 one has been fantastic and the other needed taken apart and worked on. The regulator now functions as it should. These regs were installed Hatsan air rifles. YMMV

Seems to be effective easy enough to install. I get 36 shots of consistent power out of my .25 bullboss with this in it.

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.

Arrived in a worn-looking box with no instructions or documentation. The part I received didn't look like the part in the product description. Downloaded instructions from Hatsan, and the part in the Hatsan instructions also was not the same part I received. Returning the item.