Kevin I believe has it right, before you shoot next time take 30 grains of the loose powder... if your shooting pellets then one pellet you might need to waste, and put that down the barrel. You can then push a sabot on top of the powder or some wads and take the rifle and shoot it off. Be careful, that wad or sabot is still dangerous.

Then I DO NOT swab the barrel but leave it dirty. I pop one more 209 primer through it to blow the breech plug clear and any loose powder hanging on the barrel out the muzzle and load. This should make your shots more alike.

Now I do not recommend this but I have a friend that after he loads his rifle sabotfor the first shot, will actually take a patch with a small amount of bore butter, and swab the barrel. He claims that helps the first shot be like all the others. He also says this way he does not fowl the barrel and can hunt all season if he gets no shot without unloading the rifle... take this for what you like, try it if you like. My friend claims this makes the first shot hit almost the same spot at 100 yards as the second and third shot.