Scratch

this belongs in "all about scratch as it's not an advanced topic... use a variable to count how many shots have been fired and when it reaches 7 don't let it fire again until reload is hit.

Anything about general Scratch programming goes in All About Scratch, no matter how 'advanced' the scripts needed may be. Advanced topics is reserved for more techical discussion such as modifications to the Scratch program, mesh, etc.

Anyway, here's a script to go along with what sparks said:

When green flag clicked
set ammo to (size of clip)
Forever
    If <key space pressed> and <ammo > 0>
        {shooting scripts}
        change ammo by -1
    EndIf
    If <key r pressed>
        wait (reload time) seconds
        set ammo to (size of clip)
    EndIf
EndForever

Well thats this solved... close?

Since it is not closed yet, I'll add a little something. When I was young and teaching myself to program, I had a difficult time because I got caught up in in the names of concepts. For example, I would think of gravity in the terms of real-world physics so the idea of incorporating that into a game seemed impossibly difficult to fathom. Velocity? Forget about it!

Now I realize that in fact, these concepts are usually coded into a game in a few simple lines of script that do nothing except alter numeric variables. The reason I mention this is because the op seems to be sharing a similar perception. I'm not saying that is a bad thing, just that scripting practice will break down that barrier which in turn frees you up as a programmer to add cool features to your project without the seemingly huge gap between "I want my game to do <this> but have no idea how to code it?"