either one will work fine for deer. 270 - 130-140 grs. 308- 150 -165grs.
use good quality ammo.
lots of good scopes choices out there , low power for close range shots.
also shot placement is very important.
Don't shoot deer or hogs with a FMJ- Full Metal Jacket bullet.
if you plan on eating the squirrels, don't use a 22 magnum, unless you can make head shots.
You ain’t going to get traction with that .
Too many folks like to eat deer meat .
The problem is folks hunt when they can get off work.
So it’s hard for them to pass a deer up .