Hey Rymdkejsaren, I too an some what of a gun nut, with a personal collection of over 80 firearms of all types. So, I know you pain :p
But, surprisingly, some of the tech that is shadowrun has been around for 30+ years in the Real firearms world. And there is some universal changes to weapons you should be aware of.
First off, take almost all of your prior knowledge of guns, and get ready to get rid of it
I can't put my finger on the exact in game date of the change, but electronic firing became the norm sometime around 2058 (that is when most of the guns, and supplements printed in 3e started mentioning electronic firing either in the stats blocks or the fluff write ups). Since then, ALL firearms are electronic firing, which means there is no mechanical hammer that is released with a press of the trigger: Instead a spark is created which ignites the round.
This is possible because all ammo in the 2070s is caseless ammo, meaning there is no brass and no firing cap. All there is a form factor abutment of propellant attached to the end of the bullet.
This also means there is no expended brass to trip over, or get down a shirt collar, or to run ejection mark matching.
None of this really is new tech as Heckler and Koch developed the G11 assault rifle in the 1970s which fired a 4.7mm caseless round through electronic firing (piezoelectric).
Aside from this, there is also the "balance of play" issue. This is the 5th edition of the rules, and the hacking of gear in such ways is new to the last 2 editions. this is implemented because of a huge problem that was found in the older editions of the rules; The decking mini game.
During the first 3 editions of the game, thanks to design elements, deckers really were a "solo" class unto themselves, with little other purpose then to hack doors and steal data. But in just hacking the average door required upwards of 30 minutes with dozens of rolls as the Decker hopped from node to node looking for the right file to hack..... which meant you hoped you played somewhere with a game console while the other 3 - 4 players waited 30 minutes for the decker to open the door. And, thanks to the way character where built back then, a Decker really couldn't branch out to be effective anywhere other then the matrix.....
So, they looked at ways of increasing Decker usefulness outside of just being a passkey and a xerox machine.
Hacking of gear was a logical step, along with cleaning up the matrix and how its was hacked. (and those that think it is a mess now... how much you have forgotten - Or never knew!)