No worries.
Here's the Big Game brochure from DOW/CPW:
http://cpw.state.co.us/Documents/Rul...me/biggame.pdf
If you will just be target shooting, you should be fine if it isn't rifle season, but again, I'd call ahead and just confirm where you'll be, what you're doing, etc. during big game season, and get the name of whomever you speak with. It should be fairly obvious you are target shooting. If you plan to do any small game/furbear/predator hunting, any rifle over .23 caliber is a no go during that time. Otherwise, I like to have a small game license outside of big game season to circumvent any accusations which are unfounded as far as small game intent.
Page 16 proper (not in viewer, but actual page #) of the brochure states:
1.Centerfire Rifles
...
e. It is illegal to hunt game birds, small-game mammals or furbearers with a
centerfire rifle larger than .23 caliber during regular rifle deer and elk sea-
sons west of I-25, without an unfilled deer or elk license for the season. A
small-game, furbearer or unfilled big-game license is required.
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My rule of thumb is I don't take any rifles on public land which are .23 caliber or over during big game season to avoid some Wildlife officer trying to get a feather in his cap. A lot of them are great guys and I've not met a bad one. I just don't want to meet a bad one and have it be a gray area where I know my intent but he can say otherwise.
If you have a good backstop (like a hill), are the required distance from the road, and aren't acting a fool, you should be fine. As always, if you are out and approached by an officer, put down the weapon and keep your hands where he can see them.
Pg 17 proper gives a list of illegal activities for shooting/transport of weapons/etc.
