You might well be right.
I can't remember what my source was, but it might be outdated or inaccurate. It might have been Wikipedia (
https://en.wikipedia.org/wiki/Attempted_assassination_of_Donald_Trump_in_Pennsylvania) which says
External Quote:
Aaron Zaliponi, a member of Butler County's Emergency Services Unit, fired the first shot four seconds after Crooks began shooting at Trump. The bullet is believed to have struck Crooks's rifle stock, causing it to fragment and send debris flying, which hit his face, neck, and right shoulder. The impact forced Crooks to stop shooting and reposition himself. Located on a building behind Trump's left shoulder, a team of Secret Service countersnipers were facing in a different direction and reoriented toward Crooks to aim the second shot at him before he could resume firing; a member of that team then fatally shot Crooks 16 seconds after Crooks had begun firing.
-but your reference is much more authoritative!
Right again, for
most practical purposes.
The .223 cartridge was developed by Remington in the late 1950s. It was used in the original (military, not civilian spec.) prototype ArmaLite AR-15 rifles.
External Quote:
In July 1962, operational testing ended with a recommendation for the adoption of the ArmaLite AR-15 rifle chambered in .223 Remington. In September 1963, the .223 Remington cartridge was officially accepted and named "Cartridge, 5.56 mm ball, M193". The following year, the ArmaLite AR-15 was adopted by the United States Army as the M16 rifle, and it would later become the standard U.S. military rifle.
.223 Remington, Wikipedia.
The current NATO 5.56x45mm cartridge, designed by FN of Belgium and adopted by NATO (including the USA) in 1980, is the SS109 / M855. (Wikipedia,
5.56x45mm NATO). It is very similar but not identical to the .233" cartridge.
The "original" .223" cartridge continues to be made by a number of manufacturers, mainly for civilian use.
External Quote:
5.56mm NATO versus .223 Remington
The exterior dimensions of the 5.56mm NATO and
.223 Remington cartridges are identical. While the cartridges are identical other than powder load, the chamber leade, i.e. the area where the rifling begins, is cut to a sharper angle on some .223 commercial chambers. Because of this, a cartridge loaded to generate 5.56mm pressures in a 5.56mm chamber may develop pressures that exceed SAAMI limits when fired from a short-leade .223 Remington chamber.
Wikipedia,
5.56x45mm NATO ; the "5.56mm NATO versus .223 Remington" section carries on for a while and I won't pretend to understand it all, but cut a long story short, the NATO round causes higher chamber pressure, so
(1) 5.56mm NATO-chambered weapons can fire .223 Remington cartridges safely
(2) Most (but not all) .223 Remington-chambered weapons can fire 5.56mm NATO cartridges safely
(3) If you use 5.56x45 NATO in a .233 Remington-chambered weapon
not built to handle the pressure of the NATO round, you might be severely injured or worse.
Rarely have I spent so long on a post only to think, " I set myself up for that."
I'm not a gun guy, but somehow I'm not sure I feel any better...
On the serious side,
External Quote:
An examination of the ammunition collected by the FBI found .223 Remington caliber cartridges with a federal ammunition headstamp, 5.56 NATO cartridges with an Advance Armament Corporation ammunition headstamp, and .223 Remington caliber cartridges with a Hornady ammunition headstamp
...If Crooks was carrying mixed ammunition types, it suggests (to me) he was buying it "as and when" he came across it or could afford it; perhaps a "professional" assassin- or at least someone who had made a methodical plan, over some time, to attempt an assasination with a rifle- would use a preferred/ optimal type of ammunition.
