I would imagine the supposed disc craft would be capable of various speeds, don’t you? From a stop to a cruse, to full speed to a stop.
The muzzle velocity of an MG-17 machinegun also varies according to the Ammo. Let’s say roughly 3000 fps.
>>Muzzle velocity: from 855 m/s (Phosphor “B” round ) to 905 m/s (Armor Piercing Tracer “SmK L’spur” round)<<
Back to your question, I don’t know but I’ll bet there’s lots of disinformation on the subject.
As a mamber of MUFON, I find it difficult to believe that a propulsion system as radical as would be required for that disc craft has remained secret and no one has come up with it ‘again’ in sixty years. I’m not active with MUFON currently, due to physical limitations. But I was a licensed field investigator with them and my skepticism radar is tingling real good over that supposed Nazi craft. It sells books to make up fantastic stuff, but I don’t think that one is real. Look at the history of ‘The Nazi Bell’ ... this supposed craft flew even before the Bell project was said to have made substantial breakthroughs. No, I can’t believe this one is a real craft. I have more ease believing Mars was a moon of a larger planet and had inhabitants who are now a remnant flying around in our stellar neighborhood. Tom Van Flandern may have had the exploding planet hypothesis figured out. Mars as an inhabitable moon now come planetary neighbor is more believable than these Nazi extreme advanced tech stories.