Rechambering AR180B.....

black_bear

black_bear

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.....to 6.5 Grendel? Sorry, kinda new to the rechambering concept, but would this be a possibility to squeeze more power out of the AR180B to have a more powerful non-restricted AR? Does the 6.5 Grendel fit in a standard AR15 magazine, and do 6.5 Grendel mags fit in 5.56 mag wells? Are there other 6mm cartridges that would work, such as 6.8mm SPC or others? I know that the robinson arms XCR comes in 6.8 SPC, but I don't really like the look of it..... So, would this be a possiblity or no way? It doesn't really matter how much it would cost, but I was just wondering if this would be possible in a semi-automatic.....
Thanks.
 
The 6.5 Grendel is made to fit the AR action and magazines (as is the 6.8 SPC) so in theory it should be do-able. Because there is not much in the way of accessories made for the 180B yet it would be a complete custom job. You would have to take the rifle to a gunsmith and have him do the conversion pretty much from scratch - it would be fairly involved. Personally, I am hoping that Armalite will start to offer more parts and pieces for the 180B in the near future including uppers in other calibers, I would love to get a 6.5 Grendel upper for mine but I won't hold my breath.
 
Ya, I think it would be great to have an AR for hunting big game, but I'm pretty sure it would be a pretty expensive job to have done, I think it would probably be cheaper to just buy an XCR, any idea of how much this type of job would cost? I'm guessing around $1000.00, but I really have no idea.....lol
 
It won't be a re-chambering job. It'll be a new upper receiver. I suspect you'd have trouble finding brass or ammo in Canada. Lapua and Wolf seem to be the only brass/ammo makers.
There are lots of sites about the cartridge though. One U.S. site lists uppers at $843US and about a dollar U.S. per shot for loaded ammo. The ammo does go into AR mags, but there are purpose made mags at about $30US a pop.
 
More like just a new barrel, the bore size and chamber are different. Is the base on the brass the same as .223, if it is the bolt should be ok.The barrel is easy to remove with just a few tools. The barrel threads should be 15/16thx16 You will need to play with the size of the gas port but that should be about all. PM me if you want more detail on removing the barrel.
Josh
 
I didn't understand why they created these "new" wildcats when there was already the 6x45, which is just the .223 necked up to take the 6mm bullets... Not much different performance from the Grendel or SPC and about 15% of the effort and 5% of the cost.

I read a number articles about how they had to change mags etc to get these new cals to work properly in the AR platform... But they would have been a simple drop in if they'd gone 6x45... I think its another case of twisted military logic and contracts for spending... Ie. Too much money available and not enough common sense.

If you want a bigger calibre bullet for the AR180 investigate the 6x45 before these other ones... It only requires a barrel change with a new bore size. The chamber and everything else can be re-used... ***Edit Should have said chamber can be the same as 5.56 so can use a common chamber reamer, just with a 6mm pilot on it. ***

Just a different perspective.
 
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Because it is different?
That is good enough reason for some, and the challange of getting it done. :)
Otherwise the 6x45 is a great cartridge, a friend of mine used it for years shooting silhouette plates.
And you wont be reusing the chamber as it is part of the barrel.
On the negative side, when the 6.5 and the 6.8 are used in Ar-15's you can expect premature wear of the moving components so you may find the same in an Ar-180b.
 
From what I understand it is mostly pressure like on the locking lugs, cam pins and things like that, which were designed for 5.56. I had read about it in a firearms magazine and for the life of me I can't remember which one.
 
Whenever you go to a larger case head in an AR, you remove material from the bolt head too, and weaken it. An old problem in 7.62X39 AR's was shearing bolt lugs, this is a bit more extreme case head size but still displays the issue.

And black_bear: believe me when I say the XCR looks a hell of a lot better than an AR180B! :p And, although I've only owned a 180B (and a handful of RobArm M96's, RobArm makes excellent stuff), the XCR is likely far more substantial. If you can wait for it...

And as a side and piddly note, the AR180B doesn't have a ton in common with the 'AR', the AR moniker only fits due to the designation 'Assault Rifle', and even though used in Armalite's designation, applies equally to the XCR under this logic of referring to the 180B as an AR. To me, AR's are Stoner designed, buffered, direct gas impingement 5.56/.223's and 7.62/.308's.
 
Armedsask said:
Actually, the AR in AR15 and AR180B stand for Armalite, not assualt rifle.
Click to expand...

I've heard two versions of this:

AR = Armalite Rifle

AR = Assault Rifle

I could be mistaken, as there is speculation surrounding this, and it likely started as 'Armalite Rifle', but the general consensus in the US today seems to be that the designation is simply 'Assault Rifle' these days.

Again, could easily be mistaken, but have heard this many, many times from reputable folks. :)
 
I have also heard that AR is Armalite rifle. Otherwise you would see all sorts of manufacturers using AR-##. Plus all the ARs I can think of came from Armalite. AR-10, AR-15, AR-18, AR-7. The AR 7 was not even an assault rifle so why would it have this designation unless it was from Armalite.
 
'Early Colt AR-15s, their magazines, and their operators manuals were marked with ArmaLite’s name. Colt’s retained the AR-15 designation on commercial rifles. To this day Colt’s has a model designation with the letters AR, which stands for “ArmaLite”.'
Right from the Armalite web site...
 
DaveGP said:
'Early Colt AR-15s, their magazines, and their operators manuals were marked with ArmaLite’s name. Colt’s retained the AR-15 designation on commercial rifles. To this day Colt’s has a model designation with the letters AR, which stands for “ArmaLite”.'
Right from the Armalite web site...
Click to expand...

That settles that now doesn't it. :)
 
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