I had a ornate Bedford County with a 40" barrel. I had to sell it years back because of a few years of hard times. 40" is about as long as I prefer. I still own a 62 caliber full stock Hawken with a 36" barrel I use for deer hunting. I wanted to get back into squirrel hunting, so I bought a used Kibler 36 caliber with a 46" barrel. I chose Kibler because of the rave reviews I heard on this forum. I can't reload it with the rifle standing straight up, I have to lean it over at an angle. Luckily, with the swamped barrel, it balances nicely. It barely fits into my 2019 Ford Ranger. I had to make a harness that drapes over my head rest so the butt is on the floor, and the muzzle is almost touching the roof.
It leaves me to wonder how could someone transport a rifle with a 51" barrel? Roll the window down and let it stick out? Let it ride in the bed? Buy a trailer?