Winchester and Remington went head to head with their 6mm introductions. Already competing with the famous quarter bore cartridge for medium game, both variants had their work cut out.
History will prove the Winchester won, with virtually every rifle manufacturer making a rifle chambered in 243 Winchester, while almost no one chambers the 6mm Remington anymore.
The 6mm Remington holds more powder than the 243 Winchester. It is efficient, accurate and is made by necking 257 Roberts brass down to 6mm – an easy exercise. But while Winchester saw the 243 Winchester as a great all-round cartridge for varmints and medium sized game, Remington saw the 6mm Remington as purely a varmint cartridge.
Winchester fitted their rifles with 1/10” twist barrels that were able to easily propel the heavier medium game projectiles. Remington fitted theirs with 1/12” twist barrels, which was unable to fire any of the projectiles that would be needed to be used to hunt deer – another disaster decision by Remington. They pulled the 6mm Rem and tried to re-introduce it as the 244 Remington, later reverting to the 6mm Remington when they realised they had lost the race anyway.
However, 6mm Remington is a brilliant cartridge. Chambered in a rifle with sufficient magazine length and a barrel with an appropriate twist rate, the 6mm Remington out performs the 243 Winchester. Projectiles as light as 55 grains can be fired at over 4000 feet per second (fps) while 107 grain competition projectiles can be fired at close to 3000 fps (in an appropriate barrel). This is a very versatile cartridge.
Federal still manufacture 6mm Remington ammunition. Any rifle with a 30-06 length magazine and bolt face can be re-chambered in this cartridge. So if you want an all-round rifle that is a little different to the 243 Winchester, it is worth considering the Remington 24 calibre offering.