I've lived in Montana all my life and I've shot a couple deer with a Contender 14" 7mm/TCU. The traditional handgun definition you refer to only applies to areas designated "Archery/Shotgun/Traditional Handgun Only". Feel free to use your XP or Contender or Competitor or.....
If I'm wrong about this, somebody quote me chapter, book, and verse. I just looked it up in the Montana regs and if you'll look on page 15, bottom left side, that definition is intended for what are called "Weapons Restriction Areas".
In other words - go nuts. There isn't even a caliber limitation. Want to use your .17 HMR to head shoot 'em? (good luck!
) It's legal. I didn't say ethical or desireable, but it's legal. I love Montana.
***Edit***
Okay - upon further review, I see on page 7, bottom right side, the following:
"General Season: Also referred to as the “firearm season." For deer and elk this is the five-week period from late October to late November that is generally available for hunting with a rifle, shotgun, muzzleloader, traditional handgun, crossbow or archery equipment. For antelope, this is the four-week period from mid October to early November. The specific dates and any weapons restrictions for each hunting opportunity is specified in the hunting district regulations."
If this is intended to exclude Contenders/Encores, etc. in some of the "funner" cartridges, it's news to me. I guess I better find out. I will not be happy if this is true. Hopefully, the idea was to specify the weapons for which there are specifically designated opportunities, rather than to provide an all-inclusive list of what is permissible.