After doing some searching myself, I did come up with some answers myself, but there's a few others I'd like answered, plus this might end up being a good thread for other members looking to build their first AR15.
AR15 lowers will NOT accept a 308 Upper. Why? Because 308 uppers are technicially AR10s, and are therefore a different animal all together.
However, AR15 lowers will accept 223 Wylde and 300 Whisper/Blackout Uppers. Why? Because these chamberings are essentially a re-necked 223 round. (Correct if wrong.)
The question that I wish to ask: What about other chamberings? I know 22LR and 9mm uppers are also found, and can also be slapped on AR15 lowers- but what about 6.8 SPC?
AR15 lowers will NOT accept a 308 Upper. Why? Because 308 uppers are technicially AR10s, and are therefore a different animal all together.
However, AR15 lowers will accept 223 Wylde and 300 Whisper/Blackout Uppers. Why? Because these chamberings are essentially a re-necked 223 round. (Correct if wrong.)
The question that I wish to ask: What about other chamberings? I know 22LR and 9mm uppers are also found, and can also be slapped on AR15 lowers- but what about 6.8 SPC?


















































