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6mmbr ar 15 build

I bought & sold several barrels/bolts/magazines a few years ago for the PDK line of cartridges which were based on modified 6.8 SPC cases from SSA (Silver State Armory) brass. The most popular versions were 20, 22, & 6mm; custom dies made by Forster were available at that time, and still are AFAIK. There were some quality control issues with the SSA brass; the Hornady 6.8 SPC brass was quite a bit better. The 'new' Nosler 22cal round is very similar in shape & case capacity to the 22 PDK, only it's got a rebated rim so that it can be used with a std AR15 5.56/223 bolt.
 
I had a 6mm BR AR about 6 or 7 years ago. It sucked. Got rid of it and got a 6mm AR Turbo 40° instead. Shot in excess of 10,000 rounds of that cartridge in competition with excellent results. Great round.

i had a 6mm ar turbo built by Robert Whitley with a 26" krieger barrel. most accurate AR i have ever had. berger 105 VLD's at 2840 fps.

arturbo40_zpshbfijds6.jpg
 
I shot for 4 years with a 6mmRat, it was great. The National Senior Record at Camp Perry is held by a guy that was shooting 6mmRat (my friend) they were great shooting rifles. But you are on the hairy edge...why anyone wants go bigger in an AR15 platform is mind boggling....you are flirting with danger.
 
I had a 6BR bolt and barrel a couple years ago. It worked fine with adjustable gas block to tune it and 6.8 mags. I think it was made by ar performance.
 
To make the 6br work in the ar15 upper you need to use a 308 barrel extension and the 308 bolt in an ar 15 carrier .
Like others have stated there are better 6mm options that are more reliable feeding.
 
To make the 6br work in the ar15 upper you need to use a 308 barrel extension and the 308 bolt in an ar 15 carrier .
Like others have stated there are better 6mm options that are more reliable feeding.

huh?
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The BR case can be adapted to the ar15 platform. Young Manufacturing developed a bolt capable of handling 60kpsi normal operating pressure. There's several people that have reliably built Dashers and BR variants on the AR15 platform. I built the equivalent to a 30br on a 15 platform after the jackass from the the 300 Reaper stole my money.
Adam
AB, I don't doubt that it has been done in the past but Young Mfg. is no longer offering that bolt. I'd be willing to bet the failure rate and the associated warranty costs made it a bit of a boat anchor from an economic standpoint.

PS. I have one of their Grendel bolts and it's a very nice piece of work. That's the one I'm currently running.
 
April 19th, 2009
B.R.A.T. Offers 6BR and 6BRX Uppers for AR High Power Shooters

BR Armament Technologies (B.R.A.T.) of Saluda, VA is currently producing AR uppers chambered for the 6BR and 6BRX cartridges. Unlike some other previous AR conversions for the 6BR cartridge, the BR15 uppers produced by B.R.A.T. do not merely use a .223-sized bolt opened up to fit the .308-sized rim of the 6BR case. Instead B.R.A.T. employs a different bolt design that is bigger, and significantly stronger in the lug area. Shown below is a .223-sized bolt (left) and a BR15 bolt from B.R.A.T. on the right.

br15bolt.jpg


The B.R.A.T. BR15 upper receiver has been specifically designed to use the 6BR family of cartridges. It has a larger bolt, modified bolt carrier, modified upper receiver, larger barrel extension, and most importantly an all-new magazine designed specifically to handle the BR class of cartridges. All other parts are standard AR15. The folks at B.R.A.T. have developed their own magazines. These are 5-round center-feed dual column magazines that work with the 6BR, 6BR-derived cases (like 22 BR), and the 6BRX. Since the round feeds from the center, the mags can also be used for single-feeding.

Yup that was my understanding they essentially gunsmithed the bolt and barrel extension to work on the 15upper and carrier.
 
April 19th, 2009
B.R.A.T. Offers 6BR and 6BRX Uppers for AR High Power Shooters

BR Armament Technologies (B.R.A.T.) of Saluda, VA is currently producing AR uppers chambered for the 6BR and 6BRX cartridges. Unlike some other previous AR conversions for the 6BR cartridge, the BR15 uppers produced by B.R.A.T. do not merely use a .223-sized bolt opened up to fit the .308-sized rim of the 6BR case. Instead B.R.A.T. employs a different bolt design that is bigger, and significantly stronger in the lug area. Shown below is a .223-sized bolt (left) and a BR15 bolt from B.R.A.T. on the right.

br15bolt.jpg


The B.R.A.T. BR15 upper receiver has been specifically designed to use the 6BR family of cartridges. It has a larger bolt, modified bolt carrier, modified upper receiver, larger barrel extension, and most importantly an all-new magazine designed specifically to handle the BR class of cartridges. All other parts are standard AR15. The folks at B.R.A.T. have developed their own magazines. These are 5-round center-feed dual column magazines that work with the 6BR, 6BR-derived cases (like 22 BR), and the 6BRX. Since the round feeds from the center, the mags can also be used for single-feeding.

Yup that was my understanding they essentially gunsmithed the bolt and barrel extension to work on the 15upper and carrier.
And they are no longer in business.

I get it that people have adapted a wide variety of stuff to the AR lower but, excepting the Young Mfg. bolt head (no longer available), none of the solutions can be considered an AR-15. As I mentioned earlier, one can get a single shot top end for a milspec AR-15 lower in .50 BMG. Anyone care to stretch the rubber band THAT far?

Sure, $1,000 plus non-milspec uppers can be pinned to an AR-15 lower, but they are no more an AR-15 than a Remington 700 action is a Borden, or vice versa.
 
And they are no longer in business.

I get it that people have adapted a wide variety of stuff to the AR lower but, excepting the Young Mfg. bolt head (no longer available), none of the solutions can be considered an AR-15. As I mentioned earlier, one can get a single shot top end for a milspec AR-15 lower in .50 BMG. Anyone care to stretch the rubber band THAT far?

Sure, $1,000 plus non-milspec uppers can be pinned to an AR-15 lower, but they are no more an AR-15 than a Remington 700 action is a Borden, or vice versa.
Hey I have one of those Watson weapons 50bmg uppers it is a blast.
To be honest if the 223 doesn't do it in the ar15 platform the smart choice would be the 6.5 Grendel.
 
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Hey I have one of those Watson weapons 50bmg uppers it is a blast.
To be honest if the 223 doesn't do it in the ar15 platform the smart choice would be the 6.5 Grendel.
Agreed. The PPC/Grendel option is a good choice with plenty of support. The 6 AR is a nice option on the case - heck, all of them are, from .20 cal and up.

I am going to give the .224 Valkyrie a whirl, though. I'll build one late this winter or early next spring.
 
And they are no longer in business.

I get it that people have adapted a wide variety of stuff to the AR lower but, excepting the Young Mfg. bolt head (no longer available), none of the solutions can be considered an AR-15. As I mentioned earlier, one can get a single shot top end for a milspec AR-15 lower in .50 BMG. Anyone care to stretch the rubber band THAT far?

Sure, $1,000 plus non-milspec uppers can be pinned to an AR-15 lower, but they are no more an AR-15 than a Remington 700 action is a Borden, or vice versa.
If you take a 700 action, put a ptg bolt in it, a Krieger barrel on it and set it in a McMillan stock, isn't it still a Remington 700?
 
Agreed. The PPC/Grendel option is a good choice with plenty of support. The 6 AR is a nice option on the case - heck, all of them are, from .20 cal and up.

I am going to give the .224 Valkyrie a whirl, though. I'll build one late this winter or early next spring.
If they support the cartridge like they do the 6.5 Creedmoor it shoud take off.IMG_2079.JPG
 
If they support the cartridge like they do the 6.5 Creedmoor it shoud take off.View attachment 1027457

I have an upper in 6.5brx. Yes it's a non-milspec bolt and extension but who cares. Everything thing else is milspec AR. I actually have another non-milspec bolt for my grendel too. Both are from AR 15 Performance. I'd upload a pic but the ones on my phone are too big. The 65brx kills the grendel by about 200fps. I am running 107smks at 2950ish in a 20" bbl.
 
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