Quote from Xiphos on August 26, 2023, 1:55 am

The 308 Winchester is considered a "rimless" cartridge (based on the venerable 30-06) whereas the 308 Marlin Express is based on the 307 Winchester a "semi-rimmed" cartridge.

The different dimensions of the cartridges make interchangeability unworkable.

308 Winchester is far left

Note the rim size on the 308 Marlin shells.

Quote from ARMTGuy on August 28, 2023, 7:13 pm

Order kit 20237 for 308 Marlin Express. The powder funnel and shellplate are both different from 308 Winchester