7.62x54R?

[FrankenMauser]

How is this caliber with 150gr soft points for a deer hunting caliber?

More than enough.

I am starting with the hornaday .303/7.7 174gr. 4064 powder.

An excellent choice.
But... Don't be afraid to try some slower powders.
My best powder with Hornady 150s and 174s was H380. AA3100 also did quite well.

 

[Josh Smith]

FrankenMauser,

My accuracy load is 51.2 grains of H4350 under a 174 SMK. I wouldn't use an SMK to hunt, though.

Regards,

Josh

 

[SaxonPig]

The cartridge is certainly adequate but I personally would feel funky and obvious carrying a military rifle hunting. If that doesn't bother you then no problem.