Ghost Snake, thanks for the link, but eh-he I was tired and mis-read a couple of the boxes. Wishful thinking. I use the Eskimo.com stuff, it works, and what's missing I guesstimate and calculate.
But working with numbers for lighter and slower pellets, with a BC of only 0.15 you can get .30grn 500fps projectiles out to 50m with a max trajectory height of 4-5 inches at 25m, and still only dropping 12 inches by 70-75 meters. For reference, urban light posts seem to be placed about 50-60 meters apart on slow streets, 100 on faster streets. Of course, by 100m you're aiming 40 inches higher, but if the bullet goes straight and the wind is still, it just needs range estimation and skill to make hits.
For the blade bullet, I'm not sure about the design. I'd figured a design with 2 contact points, one on the head and one on the fins. Oh well, article says they were good to 100m.
http://www.airsoftplayers.com/m40a1/Ammo.jpg