Caseless ammo would likely make revolvers less effective. Which, in turn, means electronic firing would likely be a bad idea.
Take a good, long look at the reloading mechanism. The reason why it is that silencing a revolver has never worked, even with the possibility of eliminating the mechanical noise, is because the reloading mechanism created an area where the sound itself is actually going to escape via the revolving chamber. In general, gas has been prevented from escaping via the leftover case. That's why it is silencers don't work on revolvers in real life.
Now, imagine how much less effective revolvers would be using caseless ammunition, where it would be the propellant gas escaping via the revolving chamber... Probably talking a range reduction. The only way around this is to hermetically seal the revolving chamber, which even with Shadowrun's advancements is likely going to make reloading very difficult but will preserve the gun's range (meaning that it's more likely two or more complex actions just to get the revolving chamber open to reload it).
It is because of the above problems that, in real life, revolvers have been ruled out for using caseless ammunition.
And that is why we shouldn't let realism get in the way of playing the game
