[CJK440]

Whats the story with caliber engraving on AR lowers? Does it present any legal issues when building complete firearms of a different caliber?

In particular I want to build a 9mm carbine starting with a stripped lower.

I'm in CT if it matters.

 

[1quik70]

Shouldn't be an issue as long as it isn't a NFA item such as a short barreled rifle. Better yet, look for a lower that is marked for multiple calibers.