Okay, Fire Selectors don't seem to be compatible with Las weapons for some odd reason, but that's not what this is about.
Now, as you all probably know, most Solid Projectile weapons (apart from those using a revolver setup and non-combat shotguns) work by using either the recoil or gas cycling to move a round from the magazine into the chamber. Which means that when you've fired such an SP weapon, the next round you can fire is already in the chamber. This makes for a very odd situation with Fire Selectors, since they state you can freely switch between clips.
Now, say you have three clips in your stub automatic, two with man-stopper bullts and one with dum-dums. You first fire some manstoppers and then switch target to someone unarmored, so you use your fire selector to switch to the dum-dums. However, the bullet currently in your chamber is a man-stopper bullet, so your first shot should be a man-stopper shot. And you can't say that the act of using the Fire Selector ejects the round and automatically feeds one from the new magazine, since fluff text implies that most SP weapons are caseless. I understand why this isn't an issue in the rules ( waaaaaaaaaaayyyyyyy too cumbersome), but it just seems a little weird to me.
What really makes me crosseyed is trying to imagine an autopistol or stub automatic with 3 clips attached (must be a but unhandy), no to mention a stub revolver or hand cannon with three seperate cylinders that you can freely switch between...
Why, yes, I do think a bit too much about these things. *G*