So this is the first year I'm able to go bear hunting.  I will be going in southern PA for black bear. I'm guessing the yardage will vary between 50-100yrds. I have the choice between a 7mm rem mag, 308 win mag or 338 win mag. Now I know all these will drop a bear. But what wpuld be my best choice? Thanks

Assuming proper bullet selection, all 3 are way more than adequate, both for the target and for the range.

So, I would pick the rifle that fitted me best, and handled best.

Caliber consideration, among those 3, is not a consideration.

If anything, you might consider a lesser cartridge.

I hear .308 is plenty but I have never done it.

Seconded.

All 3 are fine, your best choice is which one you shoot best

Hunting bears in PA is a ton of fun, welcome and enjoy!  Where will you be at in southern PA?

All three calibers are sufficient.  As long as you are not walking out there with a .243 - you should be more than good.

Between my family, friends, inlaws, and I we use or have used:
30-06, .308, 30-30, 45-70, .338 win mag, 7mm mag, 7mm-08, and .375 H&H mag.

PA is a great bear state - a very aggressive management plan by the PGC has paid off.  You could be running into a 150lb yearling or a 900lb bruiser.  At the local check station in central PA that I go to, there are always several 300+lb bears checked in and usually a couple that go north of 500lbs.

Edit to add:  Also consider what "type" of gun you will be carrying for the terrain you are covering.  If you are going to be going up and down ridges through mountain laurel, picking a smaller lighter gun for all day carry might be something to consider.

Gad to hear it! Ill be hunting in the Somerset/Johnstown area. I have some family up there, who dont bear but are avid dear hunters and can help me scout.

Wife and I moved to Alaska from Western Pa twenty some years back, you want to kill bear, come to ALaska, got way more bear than in Pa and people shoot them mostly all year long when warm. My kids have shot close to 20 bear with the 6.8 stag over last 5 years or so. They run 20 yards , let out their bawl.   The Local Indians have killed more grizzly with their grandpaps 30-30s than all other guns combined. I just couldn't imagine wearing orange after calling AK home anyway, sure is different up here than Pa.

the one you shoot the best and have the most confidence in.

A .308 will do nicely