Oldrookie-
The green sabots, if I am not mistaken, are for using .44 Cal (.429) bullets in your .50 Cal. As far as the XTPs I have shot, but never hunted with, .45 cal 240 grain XTPs in my Omega and they were very accurate. You can also buy the lead XTP Cheap Shots of the same dimensions for practice and switch right over to the more expensive XTPs and be right on target. I did a lot of inquiring on this subject last season while trying to decide whether to use the XTPs or the T/C Shockwaves. I opted for the 300 grain Shockwaves but they both are very accurate. I took a doe this past year with the Shockwave and was so impressed, I probably will never use anything else.