Most varmint hunters are aware that the Winchester 220 Swift has the fastest muzzle velocity of any factory cartridge. With a 40-grain bullet, the Swift generates a bit more than 4,000 feet per second at the muzzle. The Swift has reigned as “king” for many years, but its reign apparently is over. A new kid on the block may steal the title from the Swift.
Ruger's new 204 caliber boasts a muzzle velocity of 4,225 fps with a 32-grain Hornady bullet. While the figures show the 204 to be much faster than the Swift, it is also worth noting that there is an 8-grain difference in bullet weight. It's entirely possible that the Swift could easily duplicate the 204's velocity if it used a 32-grain bullet. To me, it looks as if there might be a tug of war going on between the 204 and 220 Swift fans, Also there is a ballistic side to consider.
Let's take a look at the new entry.
The Ruger 204 is a 20 caliber bore. The only other 20 caliber I'm familiar with is the Remington 5mm. Magnum which is now discontinued. Several experimenters have been pushing the 20 caliber for several years. I've read several articles on the wildcat version, and velocities reported were well above 4,000 fps. In fact. one load combination showed a velocity of 4.406 fps. That's screeching hot, and I would think would be hard on barrels. If you recall the 22 Cheetah wildcat boasted a muzzle velocity of 4,250 fps. The first one I had lasted less than 100 shots. I didn't know it at the time, but the Cheetah required constant cleaning. I took better care of the second barrel, and it still seems to be fairly accurate after possibly, 500 rounds through it. Although published velocities were above 4,200 fps, the best I could get with the suggested maximum load was 4,125 fps.
When I read of the 20 caliber wildcat's high muzzle velocity, the first thing that entered my mind was chamber pressure. It's not all that difficult to increase the speed of a bullet, but many times when increasing the velocity too much, there is also an increase of chamber pressure, and chamber pressure must be considered when working up a load combination.
Now that Ruger is offering a 204 (20 caliber) rifle, I'm sure the 204 Hornady cartridge produces safe chamber pressures. Usually, 60,000 pounds per square inch is considered maximum chamber pressure, and most ammunition makers try to stay well below that figure. Since the powder in a factory cartridge is not exactly the same as handloaders buy (that also includes the primer), will hand loaded ammo reach the same velocity level as the factory cartridge⢠I am not question Ruger's figures. I believe implicitly that the velocity figure (4,225 fps) being published by Ruger was actually obtained in controlled fixing tests. However, it must not be assumed that every rifle will produce that much velocity. When published loading data on the 204 cartridge become available to the public, we will then know what handloaders can expect. In the meantime, those who are still working with 20 caliber wildcats should use extreme care in how much powder they use.
Even if published data shows a maximum charge of 26-grains of brand X powder will produce 4,225 fps, it's wise to start well below 26-grains and work up to that. No two rifle chambers are exactly the same- Also, no one should attempt working up a load without the use of a chronograph, It's a mandatory piece of equipment for handloaders.
Since 30-grain. 224 caliber bullets are now available, handloaders for the 220 Swift will be able to find what type of velocity the Swift will give with the lighter bullet- Let me remind you that speed isn't the sole criterion for measuring the worth of a load combination; accuracy is. It makes no sense at all to just go out for sheer speed. Both the Swift and the new 204 Ruger are long range varmint cartridges, and each should be capable of producing typical hunting accuracy at 400 yards- or more. I know the Swift is capable of that with 55-grain bullets, but the velocity is well below 4,000 fps.
We'll just have to wait and see how many bullet weights are offered for the new 20 caliber rifle.
