.223 is going to destroy those foxes fine. If your keeping fur a nice Rem .17, .22 hornet or even a 17 hmr or 22 mag would be better. With a .223 you might try using a deer bullet in the 60+ grain range to punch a nice hole through the critter. At any rate:

-Take the tikka (assuming the scope is mounted) and put up a target at about 30 yards.

-Set the rifle up on a rest or sandbags so it stays upright and steady on it's own.

-Pull the bolt out and get back behind it and look strait down the bore.

-Position the rifle so that the target is centered in the bore.

-Adjust the scope so that it's on target (without moving the rifle at all.)

-Fire and adjust so it's a bit low.

-set up a target at 100 fire and zero a tad high.

-now fire at 200 and zero it at that range and you should be good from point blank to 225 or so.

Opinions vary, but I would also suggest cleaning with an ammonia based cleaner like Sweets 7.62 between each shot until your cleaning patch starts coming out sky blue instead of navy blue.(copper fouling) At that point it's broken in and should group well and hold zero.

Congrats on your certification. You guys have some crazy gun laws over there:loco Look on the bright side. Now you can go buy a supressor:excellent