[Lazamataz]

See I knew I could start an argument.

LOL!

Furthermore, 5.56 or .223?

[Scrambler Bob]

Furthermore, 5.56 or .223?
= = =

All of them. The AR has ‘diversity’.

[OSHA]

Collect ‘em all!

Centerfire cartridges imperial measurement

.17 Mach IV
.17 Remington Fireball
.17 Remington[1]
.17-223[3]
.20 Practical[4]
.20 GPC (wildcat)
.22 GPC (wildcat)
22 Grendel (wildcat) aka 224 Grendel
.22 Nosler
.22 PPC
.204 Ruger[1]
.222 Remington
.223 Remington – Original AR-15 cartridge: .223 cartridges may function in a 5.56×45mm rifle, however 5.56×45mm cartridges may produce excessive pressure in a .223 Rem rifle. On the other hand, a .223 Wylde chamber is used on .223 Rem rifle barrels to allow them to safely fire either .223 Remington or 5.56×45mm NATO ammunition.[5]
.223 Winchester Super Short Magnum[5]
.224 Kritzeck (wildcat of a .223 Remington with shortened neck)[6]
.224 Valkyrie
.24 GPC
.243 LBC[3]
.243 Winchester Super Short Magnum[5]
.25 Winchester Super Short Magnum[5]
.25-45 Sharps
.257 Ocelot (wildcat)
.25 GPC (wildcat)
.26 GPC (wildcat)
.27 GPC (wildcat)
.277 Wolverine (semi-wildcat)
.277 MSR (Dasher Wildcat)
.28 GPC (wildcat)
.30 American[7]
.30 Carbine[1]
.30 GPC (wildcat)
.30 Remington AR[8]
.30 Sabertooth (wildcat)
.300 OSSM[5]
.300 AAC Blackout (7.62×35mm)[8]
.300 Whisper[8]
.300 HAM’R – Wilson Combat[9]
.338 SOCOM (wildcat)[10]
.338 Spectre (wildcat)
.350 Legend[11]
.357 Automag (wildcat)[12]
.358 MGP (wildcat)
.358 SOCOM (wildcat)[13]
.358 Yeti (wildcat)[14]
.375 Stalker (wildcat)
.375 SOCOM
.400 AR (wildcat)[15]
.40 S&W[16]
.44 Automag (wildcat)[17]
.44 Remington Magnum (wildcat)[18]
.44 SOCOM (wildcat)[19]
.440 Corbon Magnum (wildcat)[20]
.45 ACP[21]
.450 Bushmaster[1]
.458 SOCOM[22]
.475 SOCOM (wildcat)[23]
.499 LWRC
.50 Action Express
.50 Beowulf[24]
.50 SOCOM (wildcat)[25]

Centerfire cartridges metric measurement

5.45×39mm[1] – intermediate
5.56×45mm NATO – Original M16A1 cartridge: Can also safely fire .223 Remington, intermediate[1]
FN 5.7×28mm – PDW
6mm Mongoose (wildcat)
6mm ARC – rifle
6mm Dasher
6mm AR (wildcat)
6×45mm – intermediate
6.5mm Grendel[1] – intermediate
6.5 Timberwolf (wildcat)
6.8×39mm (.277 Wolverine)[26][27] – intermediate
6.8mm Remington SPC[8] – intermediate
7mm Valkyrie (wildcat)
7.62×33mm (.30 Carbine) – carbine
7.62×37mm Musang (wildcat) – intermediate
7.62×39mm[8] – intermediate
7.62×40mm Wilson Tactical[8] – rifle
7.92×33mm Kurz – intermediate

An “AR-9” 9mm AR-style rifle.

9×19mm Parabellum[2] – pistol
9×39mm[28] – subsonic rifle
10mm Auto (10×25mm)[21] – pistol
10mm SOCOM (wildcat)[29]