I am thinking I would like to have seen all the events that led up to the point when the video starts.
Oh, read the info for the background.
If you trust what he says in the info to be the complete truth, then there are issues with the officers actions...at least initially. It really depends on what information (if any) the officers received before making the stop, and we don't know that. They stated that they had received a call, but that's about the extent of the details. What if the call said this guy was pointing his gun at cars or homes, or that he was acting strange or suspicious? If that were the case, I would be detaining the guy just like they did until I could verify his ID and make sure he was clear and valid. He became beligerant and irate...and if his side of the story is true, I don't blame him. His actions also justify a raised level of caution on the part of the officers.
There's issues on both sides.
Personally, I get his point, but he's an idiot for carry a loaded gun like that around. Why wouldn't your regular gun work?
In my opinion, it's excessive, but it's not illegal so it's his choice. I lived in Alaska and I never saw anyone carrying an AR-15 around like that, but it was legal. Most that were carrying for fear of bears or moose were carrying large caliber handguns. The area this was filmed in did not seem to be a particularly remote area where you would be in danger of becoming part of the food chain, but again, it's not illegal and it's his right.
That said, I think he's probably treated far differently by the officers if he simply has his .45 on his side and not the rifle slung across his chest.