Best place for you is the reloading forum. Your arithmetic is right but the 160 is not. 7,000 grains to a pound, but no .308 load ever uses 160 grains. And you must work up the load from a manual for your rifle. Do not just pick one and hope.
Lyman's manual is the best. They don't make powder or bullets and their book has more loads using more powders and bullet weights than any manufacturer's book. Those only have data for their products. That's the only reason though. Other than some do not test loads at all. Lee, for example, tests nothing.
Anyway, go buy a copy of The ABC's of Reloading. It's a beginner's book. About $30 is your local gun shop or Amazon. Worth every cent. And as heavyBullet says, it's not about saving money. It's about using the best possible ammo.