Let's see: In The Matrix as mentioned, Neo is shooting a pair of Skorpions, but the .223 brass is from the M16A2s the security guards are shooting. There's so much brass flying you have to go in slo-mo and watch what goes where. The Skorp brass wouldn't be falling at his feet anyway!
Furthermore, the scene where Agent Smith puts the .50 Deagle to Neo's chest and touches off a shot- in slo-mo from an overhead view- you can clearly see the next round being fed into the chamber is a crimped blank.
Now, to Matrix Reloaded, the scene where Neo, MOrpheus & Trinity are at The Merovingian's castle rescuing the Keymaker and The Merovingian and his henchmen discover them. All the henchmen open up on Neo with a wide variety of fully automatic weapons ranging from pistol caliber subguns to full rifles, and Neo freezes the bullets in midair, and then causes them to drop to the floor.
All the bullets are the same regardless of actual caliber or type of gun that was shooting, and all are fresh, shiny, and bear no rifling marks or any indication they were ever fired.
Hellboy's Samaritan revolver, which has the relief cuts in the cylinder over the CARTRIDGES, so we the audience can see the pretty shells, but which would explode if ever actually fired due to no case support.
Terminator 2: Judgement Day where John Conner and the Terminator are arguing behind the gas station about wether or not going to rescue Sarah is a good plan, the mullet-head guy comes over to "save" Conner and Terminator nearly punches his ticket- Terminator and Conner argue about killing- in the switching of shots, the hammer on the 1911 is up-down-up-down...