In my experience with firearms, cartridges, calibers, and ect I find(found) that it takes mainly just years of research and hands on experience to develop a fair amount of knowledge on the subject. Books, videos, forums, gunshops, and all are good places to do your research. I've had an interest in firearms since I was a young child and it's taken me probably 10-15 years to acquire all the knowledge I have on firearms.
"It's a gun you loaded on Sunday, and shot all week."
"If God didn't create man equal then Sam Colt had made them equal."
"Fast is fine, but accuracy is everything."