Steve-I understand your video is purely to demonstrate what we all learn in life: "Wise man cry once, foolish man save money but cry often", however, to batch test different pellets in any rife, you need to ensure you clean the bore properly and then re-lead in the barrel before you shoot groups-2-3 pull through's should get the barrel clean enough and 20-30 pellets of the brand to be tested should be sufficient to condition the barrel.

Well done on the video, you are obviously an enthusiast