I was working on a gunslinger build, and for the first time i started playing around with cyberarm rules. When I saw the Gyromount, something occurred to me.

Take a cheap SMG with an integral laser sight. The Sandler TMP will do just fine. Throw on a foregrip, a personalized grip, a gas-vent 3, and a hundred round drum and you're putting out full auto without any penalties from recoil. You may also want to consider shortening the barrel.
Now, take Krav Maga for the ability to take aim as a free action, which you'll be using to ignore range penalties.
Finally, load up that hundred round barrel with tracers. I suppose you could plausibly have the tracers at a 1 to 2 ratio with other ammo, but for my money you want a hundred tracers in the barrel (IMG:style_emoticons/default/smile.gif) .
Full auto with tracers gives +3 dice when over short range (10m, or 8 with a shortened barrel), and the laser sight gives +1 dice within 50 m. You're taking no range penalties due to your free action take aim, so at ranges between 8m and 50m you're getting a net +4 dice pool... and even SMG damage isn't bad at full auto! While this trick works just as well with machine pistols it's less advisable, purely because Machine pistols can't get the 100 round drum upgrade (IMG:style_emoticons/default/frown.gif)