M-2 Ball Black Tip. Good and effective out to 600yds w/iron sights. 7.62x54R silver tip, same ballistics but like 6x scope for this one.
Long-range precision shooting is an art form more than a practical self-defense skill for most people. It is most important for regular military operations.
In a likely hot scenario for outdoor urban or suburban locations, the active field will be 25-200 yards. Expect 6-20 assailants. Indoor problems will occur at 3-25 yards. Expect 1-4 assailants.
You might find it reassuring to have a spare loaded magazine or two. "Better to have it and not need it than to need it and not have it".
The old rule of thumb was "3 seconds, 3 shots, 3 yards". That covered 90% of all gunfights in former times. That rule may be changing in the future, but it is still a good start for planning.
If you are short on money or training time, it might be best to prepare according to the odds.