.358 bullets will work. 148 grain HBWC's work well.
I've never seen factory ammo locally for under $30 per box but you can find it online for under $20.
Many of the guns chambered in this caliber were made before the exacting standards we have today. I'd try and figure out the cylinder throat diameter on your gun and use what ever bullet fits that the best. The nice thing about the hollow base wadcutter is that the soft swaged bullets will expand to fill the throat and bore easier than any other bullet out there.