Might check w/ the local competitors on the gun type. Porting the barrel might put you at a disadvantage for class/division in Competition. Also ports would be bad if you had to use the gun @ night for protection.
So Shooter is right, a good trigger job makes a whole lot of difference in grouping. Most Bullseye is done @ 25 yards. 2-3" groups would be pretty good from offhand, I think.