The .204 Ruger was introduced in 2004 as a very accurate cartridge for varmint rifles. With high muzzle velocities ranging from 3,600 fps (feet per second) to 4,400 fps, and muzzle energy from 1,000 ft-lb (foot-pounds) to 1,350 ft-lb, it’s a flat-shooting centerfire rifle cartridge with a maximum range of about 500 yards.

What size bullet does 204 Ruger use?
204 Ruger ammo uses bullets with a diameter of 0.204 inches (5.18mm, although often referred to as a 5mm).

What is a 204 Ruger good for?
The 204 Ruger is excellent for varmint hunting, and its ballistics make it an excellent target and benchrest caliber.

Is 204 Ruger ammo good for hunting?
204 Ruger ammo is good for hunting varmints and other small animals. However, this cartridge wouldn’t be very suitable for hunting medium-sized and big game.

What is the difference between 204 Ruger and 223?
Aside from the bullet diameter size difference between .204 Ruger and .223 Remington, they have the same overall length and rim diameter (do NOT try to shoot them interchangeably). The biggest difference comes in ballistics. From a 200-yard zero:

The 204 Ruger will drop 4.1″ at 300 yards and the .223 Remington will drop 7″.
At 400 yards, the 204 Ruger drops 13.1″ and the .223 Remington drops 21.4″
At 500 yards, the 204 Ruger drops 28.9″, the .223 Remington drops 45.8″
From these numbers, you can see that the .204 Ruger has 50-60% less drop than the .223 Remington, making it more accurate at long ranges even though the calibers may seem to be pretty comparable in other respects. However, out at those 500-yard ranges, the 204 Ruger loses about 80% of its energy and the .223 Remington only loses about 75%.

Who makes 204 Ruger rifle ammunition?
When it comes to 204 Ruger rifle ammo, all of the big names are in the game