The .35 Winchester Self-Loading (.35SL / .35SLR / .35WSL) or 8.9x29mmSR is an American rifle cartridge.

The .35SL proved popular at first with the general public as a short-range deer and black bear hunting cartridge, but was soon superseded by the introduction of the more powerful .351SL in the Winchester '07.

[1] Many now consider the .35SL inadequate as a deer round, but it may still be suitable for coyote or similar medium-sized game at close ranges.

When first introduced however, the notable firearm expert Townsend Whelen noted the .35SL cartridge as displaying similar ballistics as the .38-40 black powder, low-pressure cartridge.

This ammunition-related article is a stub.