Hi folks, I recently bought a Jet2 177 on sale from Midway. It was pellet/pressure sensitive. After shooting 500 shots testing pellets and pressures it would shoot fliers even with the best pellet/pressure combination. Upon examination the muzzle crown was rough with tooling marks, a step may have been overlooked when crowned.
I contacted Hatsan USA via thier website form and was informed a day later that they would send me a new barrel. Great, I'll recrown this one, if it doesn't work, I'll replace the barrel. I stuffed a cleaning patch into the muzzle and then ground/honed the muzzle by hand with a dremel abrasive cone. After a few minutes of honing the crown was even and smooth. The gun now shoots great. Even better news, it now shoots CPHPs very accurately at all pressures (I have an abundance of CPHPs).
I have had this issue with a couple of 22lr's. Any burrs or inconsistencies at the muzzle can cause erratic accuracy issues.
Hope this is helpful
I contacted Hatsan USA via thier website form and was informed a day later that they would send me a new barrel. Great, I'll recrown this one, if it doesn't work, I'll replace the barrel. I stuffed a cleaning patch into the muzzle and then ground/honed the muzzle by hand with a dremel abrasive cone. After a few minutes of honing the crown was even and smooth. The gun now shoots great. Even better news, it now shoots CPHPs very accurately at all pressures (I have an abundance of CPHPs).
I have had this issue with a couple of 22lr's. Any burrs or inconsistencies at the muzzle can cause erratic accuracy issues.
Hope this is helpful