I got out my Sierra ballistics software and ran a couple of cases to compare the lighter (155 gr) and heavier (175 gr) bullets.
As you might guess, the 300 yard results are entirely dependent upon the velocities you pick.
I used 2900 fps for the 155 gr bullet. This gave 6.7" drift at 300 yards. I used 2700 fps for the 175 gr bullet. This gave 6.6" drift at 300 yards. I'd say that was close enough.
The thing is, if you can get the 175 inexpensively, that may be the deciding factor for shooting at 300.
When shooting at 100 yards, I am satisfied to use the 147 gr FMJ. These are fairly inexpensive. They shoot on call and, IIRC, it will hold the ten ring in my bolt rifle. That's good enough for practice.