Thread: Ar question

Im i correct in thinking if I have an ar-15 in 223 that I can buy a different caliber upper (ie 308) and use the lower for both?

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You can. But you can't buy a .308 upper for an AR15 - that would be an AR10, and not compatible.

Also you might want to be careful, in theory all uppers should fit on all lowers but cheaper brands can be out of spec

You can buy another upper, but not as large as .308, that will require a larger lower hence called the ar10

You could change uppers with calibres such as
9mm
300 wtf (whisper, blackout etc)
6.8
30 cal wilson tactical
.204
7.62x39, just to name a few
some of these calibres however will require specialised magazines aswell, and therein can lie reliability issues with mags not feeding
Most can be remedied however

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Cool thanks

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Can you get 5.56 uppers for the AR10 or would it just be better to get an entire rifle?

Not seen a 556 upper in AR10 size - not saying they dont exist.

List but by all means not everything

AR-15, without bolt modification
.17 Remington
.17/223
.20 Tactical
.20 Practical
.20 Vartag
.204 Ruger
.221 Fireball
.222 Remington
.222 Remington Magnum
.223 Remington (5.56x45mm)
.223 Remington Ackley Improved
6x45mm
6mm TCU
6x47mm
6mm Whisper
.25x45mm
6.5mm Whisper
7mm Whisper
7mm TCU
.300 Whisper (.300/221, .300 Fireball)
.338 Whisper

AR-15, with bolt modification
223 WSSM
5.45x39mm (.21 Genghis)
243 WSSM
6mm PPC
6mm WOA
6mm BR Remington
6mm Hagar
6.5mm PPC
6.5 WSSM
6.5 WOA
6.5mm Grendel
25 WSSM
6.8x43mm SPC
.30 Herrett Rimless Tactical (6.8x43mm case trimmed to 41mm and necked up to .308; the 6.8mm version of the .300 Whisper)
7.62x25
7.62x39mm
.30 RAR
300 OSSM
.357 Auto
.35 Gremlin (necked up 6.5 Grendel to 358)
.358 WSSM (various names, but all are some form of a WSSM necked up to 35 caliber, some are shortened to make them big game legal in Indiana)
.458 SOCOM
.45 ACP DI
.50 Action Express
.50 Beowulf

AR-15 using a simple blowback operation
.17 HMR
.22 LR
.22 WMR
9x19mm
9x21
9x23
30 Carbine
357 Sig
40S&W
400 Cor-Bon
41 Action Express
10mm Auto
45 GAP
45ACP
45 Super
45 Win Mag

You 'may' be able to get it to fit in the mag with a 123/125gr pill but prob too long

Originally Posted by Tussock

I see 6x47, so I assume 6.5x47 is possible?

Different 6x47, man. 6mm-222 Rem Mag, be very similar to 6mm-204.

I wouldn't use anything with a boltface the size of 6.5 lapua in an AR15 anyway. There are plenty of reports of longevity issues even with 7.62x39 bolts, it's designed for the .223/5.56 case, shoehorning larger cases in requires removing metal that is supposed to be there.

Get an AR10 platform and you're onto something (losing many very expensive cases is what you're onto)

Not keen, thanks.

Colt makes a rifle that can be both 5.56 or .308 based. CM901. Pure sex but unobtanium

I'll post a pic of my WSSM bolt when I unpack the box.
HUGE!

D-Tech - Custom AR-15 Upper Receivers - Dedicated Technology - Custom AR-15 Upper Recievers.

If only he would send me one........
but the answer is no.

You mean one of his big bolts like this one?

Btw the bolt on the right is a big one already - 50 Beowulf

That WSSM bolt is fucken chunky. Non standard upper and/or barrel extension??