you can find a lot of those sites by using search engines , like secondpower.com , or google.com , the yahoo search engine is another good one , just type in say for example " 7mm rem. mag. , it gives a ton of web pages ( i just tried it ) one i found was hodgdon.com , try it with remington arms , it gives the link to the remington arms web site. try it with the other makers too . hope that will help you