Question about round load out

[Pinglett28]

I'm still deciding on who I want to go with for my AR parts been looking at noveske for the upper. Haven't decided for the manufacture on the lower. But the question I have is on loads, looking at either 6.8mm or .308 for my AR. Haven't seen any lower kits that are those calibers. Is the caliber that your AR can load based more upon the upper assembly or do I also need to find the proper corresponding lower assembly?

[bananaman]

Standard AR lower (and LPK) for either 5.56 or 6.8SPC. The same assembled lower is used for both, the upper determines the caliber. You can share a standard lower with multiple uppers. Of course, you need caliber-specific magazines, too.

308 will require a 308-specific lower that cannot be used with a standard AR upper, along with the parts kit.

[Voodoochild]

Pinglett28 there are stickies that will answer all your questions if you read them.