YOU SHOULD ALWAYS PAPER TUNE. MY BUDDIES X-FORCE WAS A GOOD BIT OFF AFTER LASER TUNING. BUT IT'S AS SMOOTH AS EVER NOW. I KNOW A PROBLEM WE HAD WITH HIS, WAS USING NOT STIFF ENOUGH ARROWS. ONCE HE SWITCH TO A STIFFER SPINE, BULLET HOLES THROUGH PAPER. WE CHRON... HIS AT 325 @ 29IN DRAW AND 394 GRAIN ARROW I THINK. STILL REALLY FAST. NOT TOO MANY BOWS WILL SHOOT THAT FAST WITH A HEAVY ARROW. HOPE THIS WAS HELPFUL