Since the OP says hunting for a living, one has to assume they would be filmed in a variety of hunting scenarios and locations. For me, it’s a good 12 gauge and a .338 Win Mag. Can always kill smaller stuff with a big rifle, even load it down. But you can’t hunt waterfowl on camera with a rifle. Or turkeys, in some places.
OP still hasn’t clarified, but you are right – he did not specify big game. He did specify caliber, so I’ll change my answer to 0.729” and 0.308” ...
In all seriousness, it makes a difference whether one is guiding or simply hunting for video/magazine. If I’m guiding on the peninsula and I’m backing somebody on big bears, I want a 375 or larger; If I’m hunting for media, I could easily abide by just about anything in this thread.
