Winchester's NEW No. 4 was their primer for their REPEATER, LEADER, PIGEON and Metal Lined shells from about 1904 to the July 1931 Winchester catalog.
LEADER shell with the earlier No. 4 primer --
1901 LEADER 10-gauge.jpg
LEADER shell with the NEW No. 4 primer --
Leader 1901 No. 10 NPE Head.jpg
NEW No. 4 primers --
New No. 4 Primers open box.jpg
New No. 4 Primers.jpg
Winchester was purchased out of receivership by the Olin's of Western Cartridge Co. December 22, 1931. By the 1933 Winchester catalog the LEADER, REPEATER, Super-Speed and RANGER loaded shells were all being produced with
Staynless priming, mirroring Western's
Non-Corrosive priming in their RECORD, FIELD, Super-X and XPERT loaded shells.