In my Triumph the 250 grain shockwaves were tight to load. Not difficult, but tight. Tight for me equaled accurate. I tried the superglides and accuracy was non-existent. I shoot 2 pellets of 777. I would stick with the supplied sabot or go to the Harvester's. To many bad reports here on the superglides. I will check tonight and see if I still have some lying around. If I do, I will PM you and send them your way.
If you only have until Saturday, I would shoot like you are going to hunt. Getting groups looks great on paper, but I have never gotten three shots at a deer with a MZ. Personally, I would go through your entire routine (cleaning, loading, etc...) just like you are going to be hunting, one shot at a time. Then concentrate everything on that one shot. Clean the rifle and repeat. Make sure you let the rifle cool in between shots. If you do this and are getting consistent results, then you know you are good for this weekend. Once you have the confidence and knowledge that first shot will hit everytime where you aim... then go ahead and shoot for groups. I know it is tempting to rip off 3 shot groups without the hassel of cleaning, but the results will make this worth it. Keep us informed.