In the TFL Library there is a list of common abbreviations for all sorts of firearms lingo, but it doesn't always define the meaning. You can find out, for instance, that JHP stands for jacketed hollow-point, but the definition stops there.
The glossary at the website below goes a bit further:
http://www.packing.org/glossary.jsp
Others here at TFL have lists of resources that they'll share, I'm sure.