Re: Colorado magazine ban - advice for non residents ?
Those are good questions. I wouldn't count on the knowledge of law enforcement. You could get busted by State Police, local police, Game and Fish, Sheriffs. Most of the sheriffs won't uphold these laws, but that doesn't make you safe around here. I've met plenty of guys that would jack you up in a second.
If you are going to bring 15+ round magazines to colorado, I'd suggest bringing proof that you owned them prior to July 1. The law is very vague about a lot of things, since it was written by a convicted felon and all around moron.
The question about out of state is a good one, and no one has a good answer. That will have to be worked out in the courts after people are arrested.
Also, because of the background check law, you can't bring borrowed guns here for more than 72 hours (the exemption), as that would constitute a transfer if longer and thus require a background check.
If you like your hunting rifle, you can keep your hunting rifle.