During a past research project I discovered that shotshell wads were a viable candidate for a pneumatically-launched projectile I required. When properly nose weighted (usually with a dab of hot glue) and fired backwards (cup end trailing), they proved to be very accurate and stable in flight. The "petals" which form the cup offered excellent drag stabilization. Best of all, they survived multiple hard impacts.

 

This fact reoccurred to me when I was looking for a shotshell equivalent to "wax bullet" training rounds. If an empty is hull is primed and a weighted wad is inserted backwards, the package can be fired as a training round. I have yet to try this and as such I can't confirm if the ballistic characteristics carry over but I expect they will. It is highly dependent on velocity which I can't measure yet.

 

If successful, this can be an extremely valuable training tool. Perhaps safe enough to use in one's own home if the wad is padded. Drills performed in the home with the designated home defense weapon could teach far more applicable firearm handling lessons than those performed elsewhere.

 

The problem is, would it be legal? Would firing a non-metallic 3 gram projectile using primer gasses constitute a "discharge?"

http://www.njsp.org/info/pdf/firearms/njac-title13-ch54.pdf

 

On the second page. 13:54-1.2 Definitions.