Welcome to the front stuffer world! It is somewhat addictive trying different combinations of powder and bullets to see what it likes. The Optima I had that my son has now shoots 110 grains blackhorn 209, harvester crush rib sabots and 250 grain SST very well, about 1" at a 100. My Apex does real well with the same combo, although this year I have switched to Harvester PT gold 260 grain bullets. I shoot my Omega at a small farm with several houses in the area so it gets loaded lighter, 80 grains blackhorn, harvester crush rib sabot under a 300 grain xtp.

I don't have any experience with the magnum pellets, but used to shoot 777 and pyrodex pellets. I had a Knight that I killed a pile of deer with shooting pellets and 250 grain xtp's. Since the pellets don't allow you to vary your charge, you might need to try a couple different bullet/sabot combos to see what your gun likes. My guess is what you have will shoot minute of deer all day long.

The pellets will have a tendency to build a "crud ring" about 2-3 inches above bottom of barrel. Mix you some swab solution from windex and alcohol and swab about every 2-3 shots. This will make getting the bullet seated a lot easier. Also take a small drill bit, I think 1/8, and about every 5th shot HAND spin it in the 209 primmer pocket. The shotgun primers burn dirty and keeping the pocket clean helps with ignition and accuracy.

Good luck and post up any questions you come up with!