[Geech]

How does today's .223 Remington round compare to the Vietnam-era M193 military cartridge?

[Zak Smith]

These days you can buy an AR-15 with a military "5.56" chamber (loose, long throat), or a .223 chamber (tight, short throat), or somewhere in between (e.g. Wylde). You can shoot the surplus military stuff in the 5.56 chambers. Most manufacturers say you should not do so in the "223" chambers due (they're smaller with less throat/freebore).

M193 is - roughly - a 55gr bullet at 3260fps out of a 20" barrel. I have some South African M193 surplus which clocks at 3060fps out of a 16" barrel. You can also just buy the Federal XM193 (or whatever they call it), or Winchester White box Q3131A, or any other M193 duplicate.

As comparison, the Black Hills 55gr "Blue Box" only clocked at 2872 fps out of a 16" AR-15 (compared to the 3060fps from the S.A. M193). The B.H. is ostensibly loaded to commercial .223 Rem specs.

-z

[4v50 Gary]

If you're talking strict .223, my golly they've got 70 gr bullets that are loaded into that cartridge now. The AR shooters sometimes remove the front part of the AR mag so the cartridge fits. These are the guys doing 600 yard shooting plus with their "space" guns.

Then again, there's lazy and cheap people like me who want something that is inexpensive, relatively accurate and is reliable.

[Zak Smith]

70gr?

You can load both the 77gr SMK and 75gr Hornady OTM ("BTHP") short enough to cycle through the magazine.. in fact, Black Hills does.

-z