Nosler Trophy Grade 243 Winchester Ammo 100 Grain Nosler Partition Jacketed Soft Point Box of 20

Last reviewed: 2026-04-18 by Jake Terry, FFL07/SOT3, NRA-certified firearms instructor.

For hunters who need a 243 Winchester ammo load that bridges velocity and weight retention, the Nosler Trophy Grade 100-grain Partition brings decades of proven terminal performance to a flat-shooting cartridge. The 243 Winchester sits between the 22-250 and 6.5 Creedmoor in bore diameter, offering enough frontal area and sectional density to anchor whitetail, mule deer, and antelope at typical hunting ranges. Nosler chambers the Partition bullet — a dual-core, bonded JSP design that sheds its front half on impact while the rear core stays intact for deep penetration — in custom brass with a boxer primer and non-corrosive powder. Each 20-round box ships ready for the field or the reloading bench.

Performance at a Glance

Nosler loads the 100-grain Partition to 3100 feet per second from a 24-inch test barrel, putting 1920 foot-pounds of energy at the muzzle. The Partition’s mechanical partition — a copper divider between the front and rear lead cores — controls expansion: the front core mushrooms wide for energy transfer, while the rear core remains bonded to the jacket for straight-line penetration through hide, bone, and vitals. Nosler manufactures Trophy Grade in Bend, Oregon, inspecting each round during hand-packaging. The brass case accepts standard large rifle primers and reloads reliably through multiple firings. Lead-core construction requires Proposition 65 disclosure for California buyers.

Specs at a Glance

The 100-grain weight sits in the middle of the 243 Winchester’s usable envelope — heavier than 55-80 grain varmint loads, lighter than 105-115 grain target bullets — offering a balance of flat trajectory and sectional density for medium game inside 300 yards. For more 243 ammo options across bullet weights and styles, browse our catalog.