I have a couple scenarios:
1. Two friends living in Colorado, not related, meet in Wyoming to hunt. They get to WY and meet up, one guy sees his friend has a hand gun he always wanted to own and this guy has a hand gun that the other guy wants. So they decide to trade guns and they come back to Colorado with different guns than they left with. Did they break any laws?

2. The same two friends in WY hunting, only this time the one guy buys the friends gun, no trade, and comes back to CO. Did they break any laws?

I know people that have done this numerous times over the years on hunting trips outside CO, with friends. I want to know if they are now breaking any new laws, or have they always been breaking the law? Do the laws of your state of residency apply outside of your state? For these scenarios, I'm assuming all guns are otherwise legal in CO and do not have high cap mags, or other questionable features.