If a target is under 12" away you may or may not be able to fire less then two shots but it's irrelevent as you can only hit things up to 12" away if you fire one so why not fire two?
See, this is why you actually need to READ THE THREAD before you start talking.
We're talking about whether you HAVE TO FIRE TWICE under 12" or if you can instead choose to only fire once. Why would you want to fire less? Because Plasma Guns are Rapid-Fire.
You have a Guardsman with a Plasma Gun, shooting at a Marine who is 10 inches away.
Plasma guns have 'Gets Hot!'
If you fire 1 shot it overheats on a 1, if you fire 2 shots it overheats on a 1 or 2.
Your guardsman wears waxed paper for armor.
Do you risk being suddenly four times as likely to suffer a wound, just to get that extra shot, or do you play it safe and only fire once, in the hopes of killing the marine while keeping your plasma gunner alive?
This is why we were talking about whether or not you can opt to fire less than the max amount of times.
Read.
The.
Thread.
If you really really want to fire once at 0-12" I'm sure as heck not going to stop you, kind of a waste imo *shrug*
And nobody's asking whether you would let someone do it.
We're discussing whether it's allowed by the rules.
Maybe you'd be less exasperated about why people aren't getting what you're saying if you'd bother to see what the heck we're actually talking about.