Most people who shoot calibers like that reload anyways. In addition to availability, ammo prices are just ridiculous for the rarer calibers.

I don't know what you're referring to as long shots but I hope your practice time is more than described if you're shooting any distance justifying that cartridge. I reloaded a lot of 300WM ammo last winter and I just ran out of practice shells as I prepare for next week's elk hunt (I shot one at almost 700yds last year).

As you described you got the rifle by chance and not because you were selecting it as the best cartridge for where you shoot. I'm sure it will do fine at any range you care to shoot, but the meat damage under 300 yards will be extreme if you hit anything normally edible.