Good visually, but not in depth enough
Firstly, your graphics were nice - it wasn't horrible to look at or navigate through like some tutorials submitted here.
The problem I found with it was that it wasn't particularly in depth. There were about 3 or 4 invariable steps for each weapon, which were:
1. Draw outline
2. Draw inner lines
3. Fill it in
This is all very well, but for a tutorial, you need more in the way of HOW to do these things. For example, when you say to draw the outlines of a handgun, you should put some of the distinguishing features between different makes and models of handguns.
Also, "The bit where you hold it" is generally referred to as a 'handle', just so you know for future reference.
All in all, it was good, but make the improvements I've suggested in order to provide a really useful tutorial for amateur artists.