I frequently have computer crashes. Perhaps I should get a new one.
Anyways, I found out how to do many of those calculations longhand.

Here are the links to my tutorials, I find it's fun to do the this way.

http://a-human-right.org/showthread.php?t=422657
^Calculating drop, time, velocity


http://gunrightsmedia.org/showthread.php?t=420815
^For this one you can calulate how a certain load performs in a shorter or longer barrel.