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Posted: 10/19/2013 8:38:29 AM EDT
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Building a 6.8, guys.
I understand I need a new bolt (though the bolt carrier, I can use the same as in 5.56, right?) What other upper parts (besides the barrel) are 6.8-specific? Also, should I get a bolt from the same company that I get my barrel from? I seem to remember hearing something about different bolt/barrel manufacturer combinations cause problems with headspacing/timing or something. |
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first of all be sure to research your subject by visiting Here
Different parts include: Bolt Barrel Mags Buffer Maybe spring Be more specific about what it is you wish to use it for. There is a big power difference between the cartridges. Projectiles are much heavier also, nearly 100% more. Yes you can use a 5.56 BCG. I am of the opinion of a tad heavier BCG than a light one using more stock components. The rate of acceleration is higher in the light BCG, making it hard for the spring to compensate since it is not the right compression rates. It is much easier to have a dedicated 6.8 upper and just swap it out rather than going back and forth with the parts in one upper... but that's MHO. |
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Quoted:
Buy a complete ARP upper and 10 mags then go to the range. Life will be good enough your poor 5.56 AR gets lonely. Then he will end up reloading... watch and see... LOL 
Once you try a 6.8, it's either that or a 22lr for practice. It becomes, 5.56 what? I was looking between ARP and Bison for complete uppers, but a 6 months wait at the time was not acceptable when I was looking to buy. I would be way behind in preparation for this years hunt had I gone that route. I figured I could always modify it later but shooting and practice time is paramount to me. Went with a SS PSA but I am eyeing one of ARP's 20" Target barrels now. Not saying my 18" SS barrel isn't accurate, just like the idea of a 20" target for a back-up. OP, also know that a 6.8 loaded to SPCII specs is a bit more than the stock weight buffer and spring can handle. If you run an adjustable block or a piston set-up, you can make it work. I found I just needed to add mass to the buffer. Still have the stock mil-spec spring and it is working but I will go to an adjustable gas block soon. |
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Quoted:
first of all be sure to research your subject by visiting Here Yes you can use a 5.56 BCG. I am of the opinion of a tad heavier BCG than a light one using more stock components. The rate of acceleration is higher in the light BCG, making it hard for the spring to compensate since it is not the right compression rates. You need to be careful with your answers. NO He CANNOT use a 5.56 BCG. He CAN use a 5.56 Carrier. A 5.56 BCG also includes the 5.56 bolt. The term "BCG" stands for Bolt Carrier Group which includes....DUH the bolt. OP The differences are the barrel of course, the bolt is specific to the 6.8 due to a larger case rim. The magazines are also slightly different so they will feed correctly. All the other parts in the AR will work interchangeably. And to be clear with my above post the AR-15 Carriers are all made the same...basically. Slight differences in the weight and design but that's more for operability rather than function. The only part of the bolt that is different is the bolt face itself. ARP makes the SuperBolt for the 6.8 and is a better bolt. As has been mentioned the buffers and springs can be changed to a more desired use. For instance the 6.8 seems to prefer Mid length gas systems over carbine length. But many 5.56 users also prefer mid length as well. Also many seem to prefer heavier buffers over the standard carbine buffer. And for clarification to those who suggest complete ARP uppers, they do not make complete uppers anymore. Barrels yes and ones ones too. But due to parts shortages he decided to quit offering completed upper assemblies. For complete 6.8 uppers you might try IronWorks Tactical. Good guy and uses ARP barrels. |
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Quoted:
You need to be careful with your answers. NO He CANNOT use a 5.56 BCG. He CAN use a 5.56 Carrier. A 5.56 BCG also includes the 5.56 bolt. The term "BCG" stands for Bolt Carrier Group which includes....DUH the bolt. OP The differences are the barrel of course, the bolt is specific to the 6.8 due to a larger case rim. The magazines are also slightly different so they will feed correctly. All the other parts in the AR will work interchangeably. And to be clear with my above post the AR-15 Carriers are all made the same...basically. Slight differences in the weight and design but that's more for operability rather than function. The only part of the bolt that is different is the bolt face itself. ARP makes the SuperBolt for the 6.8 and is a better bolt. As has been mentioned the buffers and springs can be changed to a more desired use. For instance the 6.8 seems to prefer Mid length gas systems over carbine length. But many 5.56 users also prefer mid length as well. Also many seem to prefer heavier buffers over the standard carbine buffer. And for clarification to those who suggest complete ARP uppers, they do not make complete uppers anymore. Barrels yes and ones ones too. But due to parts shortages he decided to quit offering completed upper assemblies. For complete 6.8 uppers you might try IronWorks Tactical. Good guy and uses ARP barrels. Quoted:
Quoted:
first of all be sure to research your subject by visiting Here Yes you can use a 5.56 BCG. I am of the opinion of a tad heavier BCG than a light one using more stock components. The rate of acceleration is higher in the light BCG, making it hard for the spring to compensate since it is not the right compression rates. You need to be careful with your answers. NO He CANNOT use a 5.56 BCG. He CAN use a 5.56 Carrier. A 5.56 BCG also includes the 5.56 bolt. The term "BCG" stands for Bolt Carrier Group which includes....DUH the bolt. OP The differences are the barrel of course, the bolt is specific to the 6.8 due to a larger case rim. The magazines are also slightly different so they will feed correctly. All the other parts in the AR will work interchangeably. And to be clear with my above post the AR-15 Carriers are all made the same...basically. Slight differences in the weight and design but that's more for operability rather than function. The only part of the bolt that is different is the bolt face itself. ARP makes the SuperBolt for the 6.8 and is a better bolt. As has been mentioned the buffers and springs can be changed to a more desired use. For instance the 6.8 seems to prefer Mid length gas systems over carbine length. But many 5.56 users also prefer mid length as well. Also many seem to prefer heavier buffers over the standard carbine buffer. And for clarification to those who suggest complete ARP uppers, they do not make complete uppers anymore. Barrels yes and ones ones too. But due to parts shortages he decided to quit offering completed upper assemblies. For complete 6.8 uppers you might try IronWorks Tactical. Good guy and uses ARP barrels. Sorry, to clarify, 6.8 bolt (as I listed in the parts list, not the BCG) & a BC out of a 5.56 will work.. |
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I bought a complete rifle kit from PSA, a lightweight profile,14.7" w/pinned and welded fs, midlength gas. Just received it last week, have it on a YHM lower.
All i really needed was the complete upper assy, and buttstock assy, but now ive got a complete LPK getting lonely, time to order another stripped lower. It took about 15 business days for PSA to ship, which is what they advertise clearly, and $550 for everything except stripped lower and mags, pleased with the value!!! |
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Quoted:
I bought a complete rifle kit from PSA, a lightweight profile,14.7" w/pinned and welded fs, midlength gas. Just received it last week, have it on a YHM lower. All i really needed was the complete upper assy, and buttstock assy, but now ive got a complete LPK getting lonely, time to order another stripped lower. It took about 15 business days for PSA to ship, which is what they advertise clearly, and $550 for everything except stripped lower and mags, pleased with the value!!! Fun compact little gun you have. Let us know how it works with a range report. |
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