I have a Colt lower I am considering selling to a MD resident. I have never done this before, how do I do it nice and legal? Can my father ( a Md resident) sell it to him and forgoe the FFL?
Thanks for any info guys.

I sold a AR to a MD resident a few years back.  AR's are considered AW weapons (has nothing to do with the fed AWB) and have to be registered through the state PD.  Your lower would fall into that catagory.  I transferred my rifle to a gun shop up there.  They in turn registered it with the state AND held the rifle for the waiting period (I think it was a week).

Check into it, but even if you "give" it to your dad, he will have to register the evil lower and still go through the garbage mentioned above.

What if my buyer IS an  FFL?

I'm pretty sure gifts between father/son are OK even across state lines.  

If that is case then if father picks up gift outside of Maryland maryland law should not apply.

Of course if you are selling the rifle then it is not a gift.

This is my interpretation - YMMV.

Either way, I decided to keep it. Got way too complicated, the guy wanted to do a FTF, and I wouldnt agree to it. I also dont need to sell my lower now.