Convert AR-15 from 5.56 to 6.8mm SPC

[BumbleBug]

I've been doing some reading & I'm still a bit confused, so I'll just ask out right.

Just what is needed to convert an AR from 5.56 to 6.8mm? Just a new "Upper"? Are special magazines needed? Could just about any basic AR-15 lower be converted easily or are some brands more adaptable than others?

TIA

 

[tahunua001]

upper, yes a new upper is required. you need the entire upper half including bolt carrier group.

magazines, no, you need special mags for the 6.8, standards wont work.

lowers. yes any in spec lower should work. it'll depend on who made yours. RRA lowers for example are generally built to tighter tolerances and don't like to mate to anything but an RRA upper although some people have been able t get such conversions to work. Areo/PSA, DPMS/Remington/Bushmaster, windham, DD, and most of the other reputable makers should all work just fine.

 

[BumbleBug]

Thanks for the info...

The lower I'm considering is a PSA. I hear a lot about the "buffer"; does a new buffer spring come with a complete upper? Who makes the best mag's for this & what capacities are available?

Again TIA...

 

[tahunua001]

the buffer and spring are generally considered part of the lower receiver group so I don't know for sure if it will be included or not. you can dump the weights from your standard buffer and fill it with lead shot to add a few OZ to it. a lot of times the spring is fine but it just needs a beefier buffer. I've done this with 7.62x39 conversions and it really helped out a lot.

 

[dean1818]

You need a 6.8 Bolt, 6.8 Barrel, and 6.8 Mags

The current AR15 upper Reciever should be fine

The 6.8 is an great bullet. Puts the hurt on the Texas Piggies
(I bought the full upper)

I have the Bison Armory

I also use the standard AR15 buffer, which works well