I was looking at ArmsEast website the other day and saw they were selling two different lowers a 5.56 and 6.8spc one.
I thought the AR was modular platform in that you could swap out different upper calibres on the same lower. Now my question is do you need a different lower for different calibers?
I've seen mag well adapters so you can use a 9mm upper on your lower. Is this the same with swapping to 6.8spc?
Also I think the 6.8spc mags are different from 5.56 mags, so do they need a different mag well to fit as well?
I thought the AR was modular platform in that you could swap out different upper calibres on the same lower. Now my question is do you need a different lower for different calibers?
I've seen mag well adapters so you can use a 9mm upper on your lower. Is this the same with swapping to 6.8spc?
Also I think the 6.8spc mags are different from 5.56 mags, so do they need a different mag well to fit as well?





















































