In tenpercents thread, they were saying Lowers were no longer marked Pistol or rifle, but were checked Other and could no longer be sold to anyone under 21.
Inter family transfer is different though.
There is no "sale" there.
There is no DROS requirement either.
Only handguns are registered, so if there is no sale and no dros requirement, where is the problem?
Remember that there's also no problem with 18-21 owning handguns.
They just can't BUY handguns.
A father can gift his 18yr old a handgun and he sends $19 in to the state with the inter-family transfer form to register it in his name.