Muley,
I was told the information you posted is incorrect. LOL, Gotta love Colorado!!! Im only Talking Rifle Season ELK
You are aloud to use a 50cal ML with a saboted bullet. The bullet must weigh 210grns I believe or heavier. Like the guy said, if you had to use a full bore bullet how could you use a 50cal Inline with a sabot?? Its impossible....
But he did confirm you cannot use the XP bullets in Rifle season because they are non expanding.
Im glad this conversation came up because I would of tried the XP bullets on Elk not knowing about the expanding law.