One of the things I like to recommend to some one at the beginners stage is to get a number of different sabots having just the right sabot is just as important to good accuracy as the right powderload or the right bullet.
I often take the breach plug out of a new gun and try sabot and bullet combos by just pushing them throughit helps by eleiminating the ones that are to tight or to loose stay away form the too loose ones they can cause problems[even barrel obstructions] I have found if they are tight but will still slide down smooth they will usually shoot with the right bullet and powder load.
If eitherthe blue sabot and the 200gr 40 cal XTP or the 200 gr Shock Wave fit your gun right I would recommend them, also to try MMP 12 and HPH 24 for fit if the 24 is to tight try the Harvestor Crush Rib in the majority of guns one of these will fit but as Sabotloader said there are others if needed. Most TC will end up with the HPH 24 although a lot of the new Triumph are using the Crush Rib most Knights that I know of end up shooting best with the 12, the CVA might use any of them as might the Triditions.
A lot of people favor one bullet or another ,I favor the40 cal bullets and blue sabots because I have never ha a inline they did not shoot better than anything else at long range with and have done an excellant job on the game I have used the on. I would also recommend the 250 and 300 Gold Dot [Speer ][Work well at a wide range of velocity] and the Shock Waves[Good for long range and high velocity] and the XTP with the exception of the 40 cal 200gr which is a good long range bullet I would recommend for the up to 18 fps [meddium velocity and will open well at lower velocity.
What all the other guys said is good advice, you sort of have to bring it all together to give your self a more complete picture and remember even to guns which look th same will shoot different loads because of MZ have a wide range of tolorances on barrel diameters and the harmonics [barrel whip when fired] will be different.
Also remember that when you take a gun dowm you can chage a lot of things by changing the tension on the stock to barrel and action screws. I suggest a torque screw driver and 28 inch pounds. Lee