AR platform calibers question

[Kelly The Lionfish Hunter]

My friend is looking to get an AR. He asked me which lower could accomodate the widest variety of calibers, the AR-15 or the AR-10. It got me to wondering what all of the options are these days.

So what calibers are available for each and what calibers are possible that have not been done, like a .223 upper for an AR-10 lower?

Thanks in advance.

 

[mjh30]

Re: AR platform calibers question

AR10=308, 260, 7mm-08, 6.5-284 norma, 6.5 Creedmoor,338 Federal 243 to name a few
AR15= 222, 223, 6.8SPC, and associates eg 6.8x43, 6.5 Grendel and associates, 6mmBR, 762x39, 6x45, 17 Rem, 204 Ruger,6mm PPC, Beowulf .50, 5.45x39mm, 458 socom, then the pistol cartridges to name a few more

 

[ORD]

Re: AR platform calibers question

Alternative calibers for the .223/5.56 AR-15 lowers (this is just the tip of the iceberg really):

•223/5.56
•6x45
•7x40
•357 Mag Rimless
•300 Whisper/.300Fireball/300-.221
•6.5x40
•.30 Coyote
•.17 Remington
•.17 Mach IV
•.20 Tactical
•.19 Calhoun
•5.7 FN
•.204 Ruger
•6.8 SPC
•30 HRT
•338 Spectre
•10 mm Mag
•35/40
•219 WASP-C
•5.45x39
•7.62x39
•.338x39
•6 PPC
•6.5 Grendel/6.5 AR/6.5 PPC Improved
•22 PPC
•30 Carbine
•5.45x39/.21 Ghengis
•7 BR
•6.5 BR
•300 Sabre
•458 SOCOM
•44 Mag
•440 CorBon
•44 AMP
•.475 Tremor
•50AE
•499LW
•50 Beowulf
•.50 BMG (single shot)
•338LM (single shot)
•9mm
•45ACP
•32ACP
•22 LR
•17 HV
•10mm
•7.62x25
•224 BoZ
•7.62x24
•9x23
•.357 Sig
•.357 Auto
•40S&W

Alternate Calibers for use with the .308/7.62x51 Lowers?

•.243 Winchester
•.22-250
•.257 Roberts
•.260 Remington
•6.5 Creedmoor
•6.5 WSM
•.270 WSM
•7mm WSM
•7-08 Remington
•284 Winchester
•.300 WSM
•.300 RSAUM
•.300 Savage
•.338-7mm Benchrest
•.338 Whisper
•.338 Federal
•.338 RCM
•.35 Remington
•.358 Winchester
•.358 HDH (WSSM)
•.450 Marlin
•.500 Phantom

Again...tip of the iceberg as there are constantly new cartridges being developed or otherwise adapted for use in the various AR platform rifles (both AR-15 and large platform ARs).