I've not heard about that. A moderator has already overseen the thread, I think he would have said something about it earlier. If I am breaking he forum rules, my apologies. But to answer your questions about the projectile blooming to catch the rifling, I found these fishing sinkers that are exactly .366 and have a hollow rear end to allow blooming. Coincidence? Anyway, back to the drawing board. I'm trying to find a 9mm magazine to convert for the rifle. Shouldn't be hard. If you guys have any more suggestions or constructive criticism, please speak up. It's my first large project, I don't want to wreak havoc.
EDIT: I'm concerned about the air pressure equality. For the mkIII and other semi-autos, if the pressure is being released over and over again, will it not get significantly weaker with each shot taken?