I do not write these words lightly. I hold every man and woman who has served in the armed forces with more regard and esteem than I will any civilian. Zero exceptions. This is why this PSA burns me up.
I do not know if the words they spoke are theirs, if they believe the words they speak, or if they are paid to say them. I don't know and I won't speculate. That being said, this "PSA" is 90% lies and I will take it apart piece-by-piece.
1) The M-16/M-4 rifle is a true assault rifle. The M-4 is actually a carbine which is primarily distinguished from a rifle by the length of the barrel. These weapons are capable of firing semi-automatic (one trigger pull = one round fired), or depending on the model burst fire on the M-4 (one trigger pull = 3 rounds fired) and fully-automatic fire with the M-4A1 and M-16 (one trigger pull and the weapon continuously fires until you release the trigger or the ammunition is depleted). The rounds fired from these weapons are military-grade intermediate-power cartridges.
2) The AR-15 is a semi-automatic only version of the M-16 and was actually developed before the M-16. The inside mechanism is totally different from an M-16/M-4, the parts cannot be swapped to make the AR-15 capable to fire fully-automatic. While it is physically possible to compromise the AR-15 workings to get it to fire fully-automatic, the mechanism will likely quickly fail (as in explode during the first magazine firing full-auto).
3) To compare an AR-15 style rifle (semi-automatic operation only) to an M-16/M-4 would be like trying to compare the 0-60 acceleration times of a 1987 Yugo that has a 54 horsepower engine with a 1963 Mustang with a 354 Cleveland that produces 266 horsepower. The Yugo makes it 0-60 in 16.8 seconds, the Mustang/354 Cleveland team does 0-60 in 8.5 seconds. They are both automobiles, however in comparison they are in vastly different classes of performance.
4) The ballistic performance of the .223 civilian round and the 5.56mm M855 armor-piercing military round are also vastly different, the same Yugo vs. Mustang comparison also applies for the ammunition. If you were to attempt to fire a 5.56mm M855 round through an AR-15, the rifle would explode in your face. I promise you, that would ruin your whole day.
In conclusion of these four points, these two breeds may look the same, but they are totally different in every other aspect but looks and caliber.
Now, why in the world would someone want a weapon like that? I can answer that question in two words: Tiananmen Square.
For those of you who weren't born or able to remember 1989, it was a time of great change. Poland was breaking free of the Soviet Bloc, the USSR was going through Perestroika and Glasnost and there were calls by the Germans to reunite East and West Germany. In late 1989 (after Tiananmen Square), the wall that separated West Berlin from the rest of East Germany was torn down. Needless to say, the young Chinese heard about these things and wanted to get in on the action.
So, to protest multiple things, they did an #occupyTiananmenSquare in the capitol of Beijing. Except there wasn't Twitter, or hashtags back then. For about 6 weeks, they did what Occupy Wall Street did, without the yuppie tents and cups of Starbucks. There was great discord in the Chinese government about what to do about these protestors. The protests quickly spread to 400 cities throughout China.
Well, the Chinese government finally decided how to handle the protestors. They mobilized 300,000 troops, who went into to each of these protesting enclaves with tanks and fully-automatic weapons and killed the protestors. According to the article linked to above, over 10,000 protestors were killed just in Tiananmen Square. Those not killed by the bullets were bayoneted. If you don't know what a bayonet is, it's a long knife that is attached to the muzzle of a rifle and turns the rifle into a spear for when the trooper doesn't want to shoot you or has run out of ammunition, he runs you through the chest with the bayonet. It's a painful way to die and a common practice on how to handle enemy combatants left on the field after a battle is over.
In the aftermath of the bloodbath, those protestors who survived but did not escape China were either executed or sent to prison for years. Tiananmen Square is why you will never see another protest of the Chinese government. The slaves of the Chinese State know all too well the price to be paid for speaking out and saying unapproved things.
It is precisely this, a massacre of tens of thousands of people who were exercising something we don't even think about here, because being able to say whatever we want, especially when people protest against something the government did that they didn't like, we don't have to fear that we will be mowed down with automatic weapons. Because we have the Second Amendment and so vigorously defend the right to keep and bear arms, arms of a kind and type WE CHOOSE, not what the government thinks we should or should not have.
Do not believe for a second that if the citizens of this country are stripped of the Right to protect themselves from an oppressive government, that "Tiananmen Square will never happen here." It has happened too many times in the past 100 years for it not to happen again. In the 20th Century, upwards of 200 MILLION PEOPLE died at the hands of oppressive governments. Do you seriously want even a chance of that happening here?
During the Revolutionary War, the Militia (sometimes known as "Minutemen" because they could be ready to fight in a minute) who fought with the Continental Army had the same equipment as the professional soldiers they stood beside and against. That's all we, as citizens ask for today. Don't hit me with strawmen about crew-served weapons, anti-tank rockets and grenades. Those do not have a civilian purpose and are legitimate weapons of war. Besides, we can scavenge those from the bodies of the soldiers we kill. ;-)