Last year I bought a Hatsan mod 75 at a gun show for a very good price.
When I shot with it the 1st time my excitement turned to dispair. When fired it made a horrible twang, had terrible recoil and at best sent the pellet in the general direction of the target. At best I got 50mm groups at 10m. Every time I picked up the rifle the zero point had changed and I had to start all over. It had killed its 1st scope.
The hatsan was shoved under my bed and I went back to my trusty Gamo 640 which was good for 20mm groups at 20m all day.
A few months ago I found this site and read about Vincents MZE air ram conversions on the Hatsan. After some inner turmoil over whether its worth spending money on the Hatsan or replacing it with something else I decided to have the air ram conversion done. Vincent also adjusted the trigger for me. I also filled the stock with window putty to get rid of the hollow sound.
Since the conversion the rifle has just got better. The action has bedded and got smoother, the trigger also took some getting used to but its now almost perfect.
Initialy it shot 10shot groups of 30mm using gamo pro hunter pellets. I tried gamo pro magnum pellets and the groups came down to 20-25mm.
Over the weekend I decided to cut off the plastic front site and recrown the barrel. I cut it off with a hacksaw and filed the barrel square with a flat file. I polished the bore using a brass .30 bullet in my drill and some metal polish.
Since doing this my groups have nearly halved in size. Most pellets go into a 10mm group at 20m with shooter errors opening the groups to about 15mm.
Now I would like to see what can be done with a better scope, better quality pellets and a better shooting bench. I would also like to have the barrel shortend and a silencer fitted but this will have to wait a while.
I have attached a 10 shot group shot before crowning the barrel and a 5 shot group shot afterwards. Both at 20m