QUOTE
Ammo Skip System (Smartguns Only): This allows the character to skip through the ammunition of his gun. For example, a character could load the first 10 shots of his clip with gel rounds for non-lethal purposes, and the remaining shots with explosive rounds. When the shit hits the fan, he can skip the remaining gel rounds to get to the good stuff. In all but revolvers, the weapon simply ejects the skipped ammunition. The character simply takes a Free Action and ejects 1 round if in semiauto mode, 3 in burst fire mode, or 5 in full auto mode. If the character takes a Simple Action, he can increase that to 1 (SS), 3 (SA), 6 (BF), or 10 (FA) rounds. In the case of revolvers, the cylinder simply spins to the selected round with a Free Action.
Since the Ammo Skip system is clearly an internal/fixed magazine the device it's ejecting the bullets from actually is a clip. There's absolutely no reason to think the rest of the guns don't use a simpler device to chamber a round.
So yes, most guns of today use external magazines, but it does appear shadowrun really does use clips, just like they say.
(Anyone taking this post seriously should really ask themselves why)