I'm new to the rifle world and especially to the Assault Rifle/Battle Rifle arena.

When looking for rifles I find it very difficult to understand the various acronyms.  It's the same for ARs.  There are rifle types, like AR style, AK style, HK 91 or G3 style, FAL style but then there are all sorts of letter designations which I do not understand and which the sites do not explain.

For example, if I go to the Arsenal, Inc. site they list SA M-x rifle, SLR-101 rifles, and some have things like SAS and SFC and other designations after them.  To the untrained eye, they all look very similar and its hard to know what I'm getting.  ARs are the same, there are CARs and LARs and so forth with A2, A4 and all kinds of designations.  I've sorted through some of that, bu the AKs are still a mystery.

Is there a "primer" out there somewhere?

AR
www.armalite.com/library/history/history.htm

world.guns.ru/assault/as18-e.htm
The other models of AR rifles are covered on the menu on the left of the screen under USA.

AK
world.guns.ru/assault/as01-e.htm

G3
world.guns.ru/assault/as12-e.htm

HK 91= Hecker & Koch the makers of the G3. The model 91 is the semiautomatic version of the G3 rifle.

FAL  
world.guns.ru/assault/as24f-e.htm

SA M= Semi Automatic  Model
SLR= Self Loading Rifle
The other letter designations refer to the type of stock,barrel, muzzle brake,scope mount, etc.... the rifle has.