150 gr will be sufficient for deer out to 300 yds. 180 gr is better suited for larger game like elk. For pronghorn or coyote, 130 gr seems to work well, and for the bruins 220 gr is usually recommended. Most game is harvested within 300 yards. To set your zero, determine the range that most of your intended game will be harvested. Usually 100 yard zero is fine unless of course the majority of the terrain is further than that. If it is, then zero at 200 yards.
As for the remington ammo, it has brought down a LOT of game. Yes, there is other ammo out there, but the remingtons will do the job if you do yours.
No such thing as a stupid question. What is stupid is not asking it.