The gentleman is slightly misinformed, but technically correct. There is a difference between .308 Winchester and 7.62 nato, .223 Remington and 5.56 nato. 99% of the time they will work in the other chamber. I'm not very well versed on the 9mm, I am assuming it is the same with the parabellum, luger and nato.

They are trying to outlaw the millitary cartridges, but the 308 and 223 do not apply because they are sporting cartridges. This can be resolved by the manufacturer stamping the rifle with the civilian caliber. Now that will mean the bulk ammo will be gone unless the other countries exporting mark the ammo in the civilian name. Silver Bear has done this already with the .223, .308 and 9mm.
On some of the semi auto forums people say that a 5.56 AR is illegal for purchase in their state but an AR marked .223 is legal. Many of the guys in CA buy a 22lr AR lower or multiple caliber lower so they can have a rifle that will accept detachable magazines. Instead of popping the rear pin after every 10 rounds and loading the ar from the inside of the rifle.

I have no doubt we will see a lot of restrictions, just don't believe it will be a whole lot different than the last ban. With the acception of higher ammo, and possibly all millitary rifles banned from importation. At one time way back when, Gore was pushing a bill that would outlaw semi hunting shotguns and semi hunting deer rifles. The US firearm manufacturers crushed him since he had no viable facts to support his claims. Much as the climatologists are doing today for his global warming BS. Just trying to display the push for the dems. They spend a great deal of effort promoting lies to get the support for what they want by emotional acceptance. But by the time rationality is placed into the equation all of their hyped up bs crumbles because it is supported by oppinion not fact.
Blessings