7.62 upper on .223/5.56 marked lower

[Notalentbum]

I have several AR style rifles. I just bought a 7.62x39 complete upper from BCA. I initially mated the new upper to one of my lowers and then noticed the lower was marked.223/5.56. Is this a legal issue? I have several other lowers marked multi caliber which I’m sure wouldn’t be an issue but thought I’d check here just to be sure. I chose the particular lower based on the installed trigger and I would prefer to stay with it if it is legal.

Thanks, Matt

 

[VUPDblue]

It’s fine

 

[Notalentbum]

It’s fine

Thanks, didn’t want to be caught up in some of the NFA’s red tape legalese.

Matt