Practice Rifle Grenades

Searching for some practice rifle grenades for an M4 (even though they usually have the M203 launcher), I found a forum post on Arfcom that linked to a set on Numrich.  Unfortunately they're out of stock at the moment, but it'd definitely be neat to play with, given enough room to shoot them (a few hundred yards, at least).

The description from the poster:

Current military issue. Used by the IDF for training purposes on M16 and Galil .223 rifles. Fully-inert 14" grenades are patterned after the IMI BT/AT-44 dual-purpose rifle grenade. New set is packaged in the original wooden crate, dated 1-98, includes 6 grenade assemblies and the following repair parts: 40 plastic fins, 32 body tubes, 12 outer sleeves, 30 spacer rings, 24 locking nuts, 2 nut wrenches, 1 key wrench, 20 M16 ladder sights and 30 Galil ladder sights in 35/60/85 meter graduations (197 pieces total). Weight, 27 lbs.