As of now, there are very few options for rate of fire in guns. First, you have 1 (I won't bother with 0 for now). This spits out bullets rather quickly and is pretty ineffective with the current damage situation (which I already complained about earlier).

Next, we have 2. This is pretty much the standard rate of fire in guns in Flan's Mod. 1 is too fast, and 3 is kind of slow (I believe it's 450 RPM?).

After that, we have 3. 3 is pretty bloody slow, but with the current damage mechanics, it's not really too bad.

Anything after 3 is really slow and I don't use those much (other than bolt actions, semi-autos, pump actions, etc.)

What I am suggesting is an alternate setting for rate of fire. This would be set to a field named something like RateOfFire 900. If I wanted a gun to fire at 900 rounds per minute, I would set RateOfFire to 900. This is a much more flexible implementation of firing speeds, and for large packs, would definitely make guns more diverse.

Soon(TM) :)

The trouble here is that Minecraft only ticks 20 times a second. While possible, implementing a rate of fire system with finer accuracy would be rather complicated. Maybe one day, but not a top priority for now

I would really like to see this myself, but I was just curious: I've set the "ShootDelay" value to 0 before and tested it, but what firerate (in terms of rounds per second) does this value actually translate to? As the original poster stated, 1 is "average" for fully automatic firearms with 2 being too slow and 0 being a tad fast but hard to tell (see my first question).

Also, I don't see why it should be "rounds per minute" as "rounds per second" or "rounds per tick" would probably be a better metric to aim for.