Other than the chokes, serial number located in a different spot for the people that remove more material around the loading port that is slightly larger already, they modified the shell release to prevent accidentally releasing multiple shells at once and jamming the action if bumped the "right" way in Gen 2. The There is a cover a few companies make to prevent it in Gen 1 guns. Aridus Industries makes great accessories for the 1301, including this latch cover mod. Beretta makes a plastic guard too for about $10 US on their site for the cost effective option that does the same thing. I did a bit of reading on this before I bought my Gen 2 a while back, and people who shoot the gun in competition a lot also say the issue is overblown. I'm one of those people that doesn't like something that could happen in the back of my mind - marketers love me.