Excellent, a fun learning experience I'm certain, just tune for your application. Which is? Target, Hunting , 10M ( Kidding)
Just for fun I clicked to the altaros site and saw it adjusts from 100 to 150 bar and a 3/4 revolution range of adjustment ( like knowing roughly how far something should adjust to avoid that ham fist thing) . I've installed others ( not in a hatsan) but not an altros.
I just cant believe it is now so low cost and easy to pop a regulator from one person/company in just about any air gun. 10 years ago few factory airguns had a reg and only a couple of people made & sold them and just about all ( well all but maybe you could get one to install yourself if you knew the maker and they thought you could do it ) were in house installation so you had to ship regs them selves weren't inexpensive and only for the dedicated, and naturally you had to wait. And regulated and power just wasn't done ( except perhaps the Career 707 in .25 with an "A-Team" reg at 50fpe max). THE thing really opening long range shooting of airguns. But they do still need tuning after install - thus the afore mention "in house" work- and it is all basic ( or was "basic" back when "tuning" was not interchangeable with "adjusting") tuning that applies to any pre-charged regulated or not and it is a lot of fun getting hands on knowledge of all this "balancing" of parts.
Keep us posted, maybe take a picture or two, always like pictures.
John