Just curious - what caliber? I have never seen this gun in person, but here's my opinion; the gun weighs nearly 11lbs. - add a scope, rings and mount and it's a bench gun - there's nothing wrong with that except that a bullpup, in my opinion, is not a good configuration as a rifle which will enable mounting the scope close to the bore, enhancing accuracy and be more comfortable. Giving it some further thought, a carbon fiber bottle will reduce weight, but add $150+ at least and the gun will still weigh 10lbs. Considering the Hatsan brand only, a practical alternative might be the bullboss with an extra air tube which would give you about the same amount of air, and when one of the tubes starts to leak, you still have a functional gun - just a thought. Another option if you want a bottle, but are willing to give up the heavy bullpup is the Nova; a very large gun, but not quite as heavy as the Air Max. The Nova is a huge gun, not for small people, but it will have more power than the Air Max and is a good choice for a Hatsan gun in .25 caliber. All of the guns mentioned can be hand pumped, if you can get 60+ shots that would be plenty unless you are hunting "whistle pigs" around slash piles in Montana, for example. Pawn shops around me have hydro tested, used dive tanks for around $100 - nobody buys a used tank around where I live that hasn't been tested and there are plenty of dive shops close by for filling. The rest of your fittings should cost - give or take - $150 depending on what you buy.
