Just go to your local ammo store and buy some 150gr soft point bullets by remington, winchester, federal - nothing high power i.e. "light magnums". Go shoot and save your brass to reload. Use current reloading data and try for around 2800fps muzzle velocity. It is easier to load for bolt guns than semi-autos. No need to slug your bore, just clean the old copper fouling out good from time to time.