Try lots of different ammo, use a few shots to foul it after cleaning. I cleaned mine when I bought it shot about 20 rounds of assorted ammo and it started to tighten up. I was using a bipod and bags on the back end to support it. I can cover 3 shots with a nickel on the current ammo and it does that every time I shoot it. I cleaned it once after I found the current ammo and after a few fouling shots it is right back on where I like it. Congrats and good luck. Oh yeah and what a great toy for $125, nice buy.