This square primer tray is great for holding and storing primers. It has a ridged surface that allows the handloader to orient the primers so they are all belly up for easier feeding into your tool. the large design fits even the larger Federal primer boxes so it is easier to load. The tray will hold up to 300 small rifle primers at a time, although we only recommend loading 100. We have one for each type of primer we use.
Big Book Catalog, Issue:66, Page:512
Sinclair, Issue:3B, Page:031