True, but the ATF folks are NOT gun nuts - they merely enforce the laws as written. They have potentially ferocious power and not a great deal of technical knowledge.Is this fear based on any legal precedence?
There is absolutely no difference between a Charger in a Nordic stock (no butt) and an AR-style pistol. None. If anything the Charger is even more in the clear because there is no buffer tube that could be misconstrued as a butt. These are all just paranoid fears with no basis in reality.
I would NEVER attempt this project without ensuring that the Nordic receiver was _permanently_ modified to not accept a stock - just screwing in a plug does not qualify. Screwing in and tack welding would - just like screwing on a flash suppressor on a too-short barrel and then welding in a couple of spots, or installing a pin in a blind hole.
Lots of guys flirt with the gray areas of firearms law - once in a while one gets nailed by the ATF and gets to spend some quality time behind bars in a Federal penitentiary - are you willing to take the risk, no matter how small? Not me!
If you want some excellent pointers on this subject, Pat Sweeney's AR-15 Gun Digest book (Vol 1) goes into detail and it's a little scary.