Definitely check the barrel for sign of a choke in the middle, mine is an older XL model which had this problem, it now has a Mercury barrel on & was instantly transformed so it groups sub inch at 20M, & is now a Supersport. Push a pellet through with a cleaning rod, it shouldn't tighten up until the last inch or so. I'm using RWS SuperH Points nowadays on rats, but usually at 10M or less.