Have had three gun-related "run-ins" with NB COs.
1). Was simply walking into woods looking for a place to sight in rifle on first day of bear season. Didn't find such a place, walked out, then was greeted by COs who had been called by a woman who thought we were going to shoot the beaver living in a pond behind her house. Riiiiiiiiiiiiiiiiiiiiiiight.

Had no complications or problems whatsoever - we told them what we were doing and they said it was OK. They also thought my SKS was pretty cool.
2). Later that bear season, was sighting in at a government-approved pit. Alas, I had forgotten my wallet at home - no driver's licence, no bear licence. Stupid, but it happens to everyone once in a blue moon. So when a CO came along, he was quite understanding and didn't ticket me, but confiscated my guns until I produced my licence. He said I could pick them up at the station. When I told him I couldn't get them home from the station (only vehicle I had at the time was a motorcycle) he then drove to my house, waited for me to get home, then returned my guns once I produced my bear licence and my registration certificates. So technically he wouldn't have had to ask for my reg certs if he hadn't had to seize my guns, which he wouldn't have had to do if I remembered my licence. The guy was polite and extremely helpful through the whole thing and I got nothing more than I deserved for forgetting my wallet. In fact, I got a huge break.
3). While driving on the highway this past August I decided to kill two birds with one stone - get some crow hunting in to practice for upcoming duck season, as well as try my new 16 gauge out. Alas, some civic-minded individual saw me
unloading my gun getting into my truck, reported me to the cops as
loading my gun, who then sent two cars after me, held me at gunpoint and cuffed me (while I neither said anything smart or did anything threatening) and then proceeded to hold me until a CO came along and told them I wasn't breaking any laws. They gave me a lecture on "unsafe transport" because my gun wasn't cased and locked (I set them straight on that one, too), they gave me a lecture because I didn't have a CFC-issue sticker on my shotgun (there wasn't one on it when I bought it, so I didn't know it was missing), but neither the CO nor the RCMP asked for reg certs here (the RCMP did apologize, though, and the CO gave me some coyote-hunting tips).