If I'm not mistaken Len Backus has hunted in CO. with his son last year. Len might know what can be used in that state on a TAC15
crossbow. Len also maintains very close relations with some of the engineers at PSE and they also might have a solution. I would find it hard to believe they don't sell TAC's in that state, just because of the lack of open sites.
You can open a post in longrangehunting.com to Len Backus. He or his son Andy will respond very quickly to your questions.