If you MUST use pellets, then try both 2 and 3. If you must use powerbelts, try a few weights out.

I'll stick to loose powder for starters. However, I'm not sure if it's legal to use sabots where you are, but if they are legal- try some Hornady SST/MLs. A little more aerodynamic. Drop is easy, adjust the scope, wind drift requires a little bit of a feel

So, don't be afraid to shoot more than a little and figure out what you and your gun want to shoot.