I loaded a stock 30 rnd Drozd mag with the BP shot today with a speed loader without screening. It loaded as easy as steel. I then loaded it into a stock Drozd. I made it halfway through the mag before someone needed something. It worked much better with the stock follower spring. I had one hangup where the shot enters the valve body. I don't think that will be much of a problem if I dish the input out with a drill bit.
With a completely stock Drozd I averaged about 445 fps. Again I was expecting a smaller number.