I've run into the exact same thing. Despite common sense telling us that all paintball guns shoot the same at the same velocity, when my gun was acting like yours and I tried to turn it up, it resulted in a very weird slamming feel, excess kick, and a notably arcing trajectory. Unfortunately, my "sweet spot" was around 250 rather than 280, and as soon as I went above it whacked out on me.
Originally Posted by agentSmith
oldschool play is about sportsmanship and respect, oldschool gear is available on Ebay.