I think the most popular caliber for moose in Ontario would be the 30-06. I use a .300 Win mag. which is also popular. I hunt the clear cuts and although most shots are 150 yds or less you can easily get out to 400 yds . I shot a nice young bull at 138 yds this year according to a range finder. Another in our group took a 31/2 yr old bull at 50 yds with a 30-06. In our group of 5 hunters there are 2 30-06, 1 .270,1 .308,1 .300 mag.