AR in .300 Win Mag?

[vanguard70]

Ever heard of anyone chambering an AR style rifle in .300 Win Mag? I would think it's doable since the .300 Win Mag cartridge works in standard length action rifles. It would seem to have better performance than a .308 (AR-10). Sounds like it would be a pretty nice setup.....tell me why this is a stupid idea.

 

[IXLR8]

Ouch. That's all I am saying. The buffer spring would be like a strut off a Toyota...

 

[txgunner00]

I believe there are .300 WSSMs and I know there is a .300 OSM, but a .300 Win Mag won't fit even in an AR-10 platform. You could build a .300 win mag bolt action upper for an AR lower though.

 

[vanguard70]

I know it would kick more than a .308 but there are .338 and .50 Beowulf ARs out there. I need to improve my google fu...I'm sure someone has tried a .300 WM AR.

 

[mikeofcontex]

AR-15 is limitted to "223" length cartridges. AR-10 is limitted to "short" 308 length cartridges. The next step up is the standard length, 30-06, action and there is not an AR style platform for that. The next step up is the magnum length for the really long cartridges. The 284 Win "duplicates" 30-06 performance in a 308 length action. The rebated rim is the same size as the 308 and 30-06. It might work nicely in an AR-10 platform if it could be made to feed well.

 

[Angered_Kabar]

There was a company that made .30-06 and .338 LM sized ARs recently but they've been acquired by the 'RemBushLinETC' conglomerate. Hasn't been made since.

 

[Dawico]

Cobb Manufacturing made the AR in 30.06. I believe it was the Cobb MCR 300. Reading what I can find about it was that it is a long action (30.06, 300 WM length) AR rifle that is easily changeable between many calibers. All information about them is atleast 4 years old. I spoke with one of their reps at the NRA Convention years ago and they had just been finalizing the terms of their buyout. That must have been right at the end of their existance.

I was intrigued by an AR in 30.06, but if memory serves the price tag was about $4000. It looked more like a Barrett M107 than an AR15.

 

[paratrooper4life]

A treat for everyone. Have a true "AR platform" 300 Win Mag rifle - World's Most Powerful AR by Miller Precision Arms - The Guardian MP-300 - YouTube
last half of video shows best footage.

 

[biglucky]

AR-15 is limitted to "223" length cartridges. AR-10 is limitted to "short" 308 length cartridges. The next step up is the standard length, 30-06, action and there is not an AR style platform for that. The next step up is the magnum length for the really long cartridges. The 284 Win "duplicates" 30-06 performance in a 308 length action. The rebated rim is the same size as the 308 and 30-06. It might work nicely in an AR-10 platform if it could be made to feed well.

Wow, attack of the semantics police.

Nemo arms makes the Omen, which is a 300 Win Mag AR platform rifle.

Omen // Match .300 Win Mag AR | NEMO Arms

 

[mikeofcontex]

Semantics... to some, a gas piston AR is no AR at all... if you stretch the design to be simply gas-operated, you pick up a lot of candidates.

The AR-15 is length limited... the AR-10 is length limited... The 300 Win Mag will fit in neither. These "standards" are not simply semantics.

The Omen is neither an AR-15 or an AR-10, but is an ugly black gas-operated semiautomatic weapon. I'd love to own one and have the money to own enough ammo to enjoy it.

 

[Texasjack]

There are some powerful cartridges that have been designed for the AR platform. Marty ter Weeme developed the 458 SOCOM for the AR-15 and the 500 Phantom for the AR-10 platforms. The Phantom tosses a 525 gr. bullet at 2000 ft/s - significantly more heat than a .300 Win Mag brings. These cartridges were designed to use the same cartridge length and still fit in the standard magazine (albeit single stack).

 

[M. Sage]

Ever heard of anyone chambering an AR style rifle in .300 Win Mag? I would think it's doable since the .300 Win Mag cartridge works in standard length action rifles. It would seem to have better performance than a .308 (AR-10). Sounds like it would be a pretty nice setup.....tell me why this is a stupid idea.

.300 Win Mag is long action, and I don't know of a long action AR platform. You could build an single shot upper for it if you really wanted to...

 

[biglucky]

.300 Win Mag is long action, and I don't know of a long action AR platform. You could build an single shot upper for it if you really wanted to...

Look at the link I posted bro. There are a couple companies making AR platforms in 300 Win Mag.

 

[M. Sage]

Look at the link I posted bro. There are a couple companies making AR platforms in 300 Win Mag.

Wow, who'd have thought.

Can't be much of a market for that.

 

[1slow01Z71]

Ouch for 5K you can get a couple nice "odd" caliber ARs that have even more power than a 300WM.

 

[CachookinLA]

Why do you want an AR in this caliber, OP?