SA-80, otherwise known as "+20 Rifle".
Honestly, adding +20 to all accuracies and +10 to damage? When did they miniaturize Auto Cannon and put advanced gyro on it?
All right, I could accept these stats... on one condition: if somebody implements a well-known feature of SA-80, that is a clip that sometimes falls out for no reason whatsoever.
(OK, as a bullpup it could be slightly faster, but I don't think it would be more accurate.)