I have and still do travel to Canada a lot I use the US Customs form 4457 to list not only my firearms but all of my personal items, including scopes, binoculars, computers, basically anything of value that I am leaving the US with. It is signed off by US Customs before leaving the states that way there is no doubt you had it in your possession when you left. Depending on the US Customs Agent you happen to encounter it can a walktrough or a real hassle so it is just easier to have all of the paperwork in order.
For the paperwork needed by the Canadians I would advise that you download it on line fill it out with all the required info so when you get to the border it is easier for the Canadian Border Patrol folks - As mentioned earlier though don't sign it because it needs to be signed in their presence.
Going back and forth was a breeze until 9/11 occurred after that things tightened up on both sides but I have never had an issue with the Canadian BP, wish I could say the same about re-entering the US. About 4 years ago I had been to a match and of course was bringing back my ammo that I had not used - the US BP agent was going to confiscate it because I did not have anything to show I had taken it out of the US and so he was going to impound it because I may have bought it in Canada, it took some time with his supervisor but it was not impounded. I was tied up about 2 hours waiting for the waiting for the supervisor though since he had to come over from a different crossing. The next time I went up I listed all of my ammo on the 4457 when the US Customs guy saw ammo he said - it is not necessarty to list the ammo, I did it anyway. Sure enough coming back about 10 days later same port of entry but a different agent - he wanted to see the 4457 with my ammo listed on it.
If there is a customs office in your town, like at the airport - you can do a 4457 and have the articles verified there. Neither at the border or in a town customs officer do you want to carry your items in - they will come to your vehicle to examine them.
drover
