What rifle should I bring and what should I sight it in for?
You should bring a rifle that you are comfortable shooting and can shoot accurately. I feel this is more important than the caliber you choose. However, if you are hunting on the Peninsula for brown bear I suggest a minimum of .338 with a preference for the .375H&H. Consider that almost every bear guide you run across will be using a .375H&H and that in the event you need ammunition, because you lost yours in a creek or it didn't make it to camp, you will at least have common ammunitions. A 300-grain bonded core bullet works well for me.
I prefer to keep the selection of rifles and calibers simple and avoid taking something into a remote area that you are not likely to get parts or ammunition for. Almost every village store in bear country will have .375H&H ammo, as will likely your guides, but trying to get ammo for a .415 Grizzly Blaster Special you wildcatted from one of uncle Ned's loads back in the '50's will be like trying to swim from Nassau to Nairobi. Underwater!!
If you shoot a large caliber for brown bear take the time to get used to it. I shoot mine more than most and have epoxied eight ounces of lead shot in the forearm just to keep it from beating me up too badly.
In the Brooks Range a .30 caliber will cover everything. I personally use a 30-06 with 180 grain bonded core bullet for all game except brown bear, but the .270, .300 Win, or .338 would be fine too. Most of my guides use the 30-06. I'm not a real fan of different bullet weights on a hunt. I don't like to confuse things. After the rifle is sighted in I write the data for trajectory and wind drift on the stock of my rifle. That way I don't have to worry about a failing memory and it gives me something else to read during a long storm, after I've consumed every book cereal package and matchbook in the tent. Memorize it. It will pay dividends in the end.
Most people will usually be able to tell you if an animal is within 300 yards, with a reasonable degree of accuracy. Beyond that point the margin for error rises dramatically. Therefore I use the 300-yard figure as the maximum I would normally attempt to shoot game. Limiting your shot to 300 yards and sighting for a 200 yard zero should keep your bullet within a margin of 5" above and 5" below the line of sight out to 300 yards. Please check the trajectory tables for your specific rifle. A 200 yard zero will work equally well for either your larger brown bear rifle or the smaller calibers. It is not likely that your first shot on a brown bear will be beyond 100 yards but with a 200 yard zero you will at least be prepared to dispatch a fleeing bear at longer range.
Also, put ten or twelve wraps of black plastic electrician's tape around the barrel, one wrap on top of the other, near the muzzle, so you will have a handy supply available for keeping water and debris out of you rifle muzzle. It will be blown off as the compressed gas proceeds the bullet down the barrel and won't effect the rifles point of impact.
