Is the 6.8 x 51 round the military just adopted the same as 6.8 SPC?

[rogersmithiii]

Are these the same cartridge? Once the Supremes do away with the AR15 bans, can you buy an AR15 for 5.56, and buy an upper for 6.8? Do 6.8 magazines fit a 5.56 lower? Or are the gun designs unique?

Thanks

 

[76Too]

 

[JRT]

Are these the same cartridge? Once the Supremes do away with the AR15 bans, can you buy an AR15 for 5.56, and buy an upper for 6.8? Do 6.8 magazines fit a 5.56 lower? Or are the gun designs unique?

Thanks

6.8x51 is nothing like 6.8SPC, it’s much hotter. You could argue it’s like 277 Fury but the bonded 6.8x51 is very different.

6.8x51 will fit in any 308 designed box magazine, not 5.56.

 

[rogersmithiii]

6.8x51 is nothing like 6.8SPC, it’s much hotter. You could argue it’s like 277 Fury but the bonded 6.8x51 is very different.

6.8x51 will fit in any 308 designed box magazine, not 5.56.

So 6.8 x 51 will demand a separate rifle, not just throwing an upper on a 5.56 and changing magazines??

 

[ChevyGuy91]

5.56x45mm vs 6.8x51mm. Good bit of case size difference there, it will probably fit in a AR10/SR25 mag.

 

[rogersmithiii]

Found a decent article.

.277 SIG FURY/6.8x51mm - Everything You Need to Know

What’s all the hype about the cartridge, known in civilian shooting circles as the .227 Sig Fury, and how did it come into being?

thegunzone.com

 

[NavelOfficer]

You might want to check out the .277 Wolverine.

.277 Wolverine - Firearm Wiki: The Internet Gun Encyclopedia

firearmwiki.com

One benefit to using a .277 caliber: plenty of bullets collecting dust at New England gun shops as .270 Winchester is so un-loved around here.

 

[paul73]

So 6.8 x 51 will demand a separate rifle, not just throwing an upper on a 5.56 and changing magazines??

core of the answer:
"Both the XM5 and the XM250 can be quickly switched to alternate calibers. Swapping them from 6.8X51 to either 7.62X51 NATO or 6.5 Creedmoor is as easy as changing the barrel. "

not AR15. AR10. when it will be around, we will see.

 

[mac1911]

6.8 necked down 7.62x51

you can huddle over ballistic differences.