The 17WSM competes in a category that is not popular/common in NZ, folk who shoot a lot of small and medium varmint swear by cartridges smaller than 223.
Less powder also heat up your barrel less which is factor with light profile barrels or high volumes of shooting, whether that be effecting accuracy or mirage off the barrel/suppressor.
In many cases NZ just doesn't have the same varmint/game animals that other countries do, so the smallest centrefire cartridges make less sense here.
17WSM will be a lot quieter than 223 unsupressed, the difference between 22lr, 17hmr and 223 is substantial, it's more than just the speed of the projectile that contribute to noise levels.
Whilst 223 recoil isn't typically an issue, less recoil is always preferred.
Bookmarks