Recently I bought a new LP8 and is shooting 3-4 inch high at 10 yards with RWS 7gr pellets even after 500 shots No room for adjustment of rear sight. I returned it for exchange 3 times but all the new guns I received from UMAREX have the same problem. I tried 10.5 gr pellets and is still shooting ( now 2-3 inch) high .Has anyone any idea? Am I missing something? it is unexpected from a new German made expensive pistol.