AFTER I PUBLISHED A COLUMN ON REDUCED RIFLE reloads, several readers asked about fillers and why their use has fallen off. Fillers are non-energetic solids placed in a cartridge to reduce airspace, maintain the propellant’s position, or both. They generally fall into two classes: fiber “puffballs” and granular. I want to talk about the puffballs—to me they are the most troublesome.
Puffball fillers are wads of lightweight fiber and can be natural, like kapok, or synthetic, like polyester fiberfill. Think “pillow stuffing.”
Years ago, published reloading information suggested puffball fillers for reduced loads where better ballistic uniformity was needed. You pushed a puffball of the fiber on top of the propellant charge. However, the recommendations rather quickly slowed and, in some cases, stopped.
I knew Dave Andrews, my predecessor at…
