One thing I'd recommend to anyone that doesn't already have it, is to buy QuickLoad. Used properly it will answer questions you can't get answered any other way unless you have unlimited funds and time. It's one of the things I've got that I wouldn't be without.
You can play "what if" with any caliber, barrel, bullet etc. and never leave your computer. It's a computer program and not real world stuff but once you learn to use it properly and input everything necessary it will get you very close.