I created this body of work a couple months ago, but didn't really spread it around beyond YouTube. I apologize if this is in the wrong forum, or if this information is not useful to the Wiki. These are two playlists containing detailed demonstrations, tests, and comparisons of every weapon in the game save the Resurgence weapons as I haven't had a chance to play much MP and unlock them. These videos were made purely to help ME3 players who were looking for more info on the weapons in the game and how to use them effectively.
The first link is my Target Practice series which focuses on testing the various weapons' accuracies in detail in the Spectre Shooting Range:
The second link is my Live Fire series which demonstrates the weapons in real combat and talks about mods among other things:
Finally here is a link to a video which tests Extended Barrels vs Piercing mods:
Apologies for the title being off.