a published "Pending patent appplication" from the USPTO...

a published "Pending patent appplication" from the USPTO today:

titled ~ SLEEVED PROJECTILES

in the contents:

The present invention relates to projectiles for use with barrel assemblies having a plurality of projectiles axially disposed within the barrel and which projectiles are associated with discrete propellant charges for propelling the projectiles sequentially through the muzzle of the barrel.

Our earlier patent applications relate to small arms, mortars and large bore rounds and the like and this invention relates to rounds for such weapons.

Trials of a handgun according to aspects of our earlier patent applications have indicated that the two-part small caliber projectiles have a tendency to separate in flight especially when they tumble. In one aspect this invention aims to provide a suitable projectile assembly in which the parts remain intact as a streamlined projectile during passage to a target.

full details:

http://appft1.uspto.gov/netacgi/nph-Parser...0527+AND+ICN/au)