I would leave it alone.  I stopped counting how many more droplets in the pink spray my .220 Swift makes over my buddies .22-250 due to the extra 100 fps.  The praire dogs and coyotes didn't much care, either.  
Seriously, I would stick with it.  It will not wear your throat and barrel as much, and your gun seems to like it...win, win situation.  Another thing is, and I just noticed this, how long is your contender barrel.  If it is under 16", it might be pretty hard to push 4k fps.