Recently got a Gamo Swarm Maxxim 10x. Scope worthless, could not focus. Bought a Hammers with AO starting at 10 yds. With target at 10 yds. using Gamo Tomahawk pellets had it grouping with holes touching. Scope set at 3x and 10 yds. Went to 20 yds. lost grouping, flyers left, right, up and down. Farthest right and left was over 4". Switched to Gamo PBA's, no differance. Tried some German Mauser Diabolo, tighter but still 2". Scope at 9x and 20 yds. AO. I did run a patch before using, no oil or cleaner. Any suggestions?