First Look: The .375 Ruger

By Rick Ryals

.375 Ruger
Illustration courtesy of Hornady Mfg. Co.

Have you ever had a great idea, but no way of making it a reality? Then you came across it in a newspaper article or saw it in a store. Responses to this phenomenon can vary from "Hey, they stole my idea" to "Well finally, I've been waiting forever for somebody to make this." You figure that if you, all by yourself, could think of it some business genius ought to have come up with it years ago.

Well, a similar thing happened to me with the .375 Ruger. When I first read about it near the end of 2006 I thought it interesting. I found myself thinking, "Did they do the obvious and make an unbelted, non-rebated 0.532" rim, 30-06 length .375 magnum? Or did they try to get clever and screw it up?"

I had thought about such a cartridge for the past couple of years. This seemed like such an obvious solution to me. Use the 0.532" rim size since that is a standard bolt face diameter. Instead of a belt or rebated rim, use a straight-sided case with a slight taper to the shoulder. And keep the overall length to fit a standard 30-06 action size. Lo and behold, that is what Ruger and Hornady have created.

Dimensions of the new cartridge are as follows:

  • Case length 2.568"
  • Overall length 3.315"
  • Rim diameter 0.532"
  • Head diameter 0.532"
  • Shoulder diameter 0.510"
  • Neck length 0.314"

Cartridge dimensions are as yet unavailable from either the Ruger or Hornady web sites. Dimensions shown were found in the January-February 2007 issue of the Rifle magazine article ".375 Ruger." I was unable to find the shoulder angle, but from pictures it appears to be around 30 degrees. I also found slight variations in case length (2.50" to 2.58") and head diameter (0.529") in other articles.

The ballistics of the cartridge, as found on Hornady's web site, are 2840 fps for the 270 grain bullet and 2660 fps for the 300 grain bullet. As advertised, they slightly exceed those of the .375 H&H. On the other hand, they do not produce the excessive velocity and recoil of the .378 Weatherby or the .375 Remington Ultra Magnum.

The Ruger Hawkeye rifles to be chambered for the new cartridge weigh from 7.75 to 8.0 pounds. With a scope mounted overall weight should be around 9 pounds. These rifles should generate in the range of 40 foot-pounds of recoil with the 270 grain load and 45 foot-pounds for the 300 grain load. This is reasonable in comparison with other dangerous game cartridges and rifles.

An advantage of the .375 Ruger over the WSM and RUM cartridges is that it avoids the potential feeding problems of the rebated rim. This is especially important for a cartridge such as the .375 Ruger that is intended for dangerous game.

Forerunners to the .375 Ruger are the .376 Steyr and the .375 Dakota. The .376 Steyr is based on the 9.3x64 Brenneke case and is a beltless case with a 0.495" rim diameter. The .375 Dakota is based on the .404 Jeffrey case and is beltless with a 0.545" rim diameter. Both these cartridges were designed to fit standard length long actions.

The problem right off the bat with these two cartridges is that neither has a standard 0.532" rim. This means that they will not fit standard magnum bolt faces. Thus it is unlikely that anyone other than Steyr or Dakota would ever chamber rifles for them. I am not aware of any other rifle manufacturer that produces rifles in either cartridge.

Ruger and Hornady have avoided this problem with the .375 Ruger. It will fit any standard length rifle action with a standard .532" bolt face. This makes it simple for virtually any rifle company to chamber rifles for it. Although Ruger M77, Remington M700 and Winchester M70 magnum length actions will accommodate the .375 H&H, some other makers' longest actions will not. For example, the Savage and Kimber long actions could be chambered for the .375 Ruger but not the H&H. Thus the .375 Ruger opens the door for companies without extra long actions to chamber a dangerous game cartridge.

Only time will tell if the .375 Ruger will be successful. Dangerous game cartridges obviously don't see the use or sales that medium game cartridges do. But Ruger and Hornady have created a cartridge that avoids many of the potential problems of other recent cartridges. It should feed reliably. It avoids excessive velocity and recoil. And it will fit any standard long action with a standard magnum bolt face. It has the potential to become the benchmark for dangerous game cartridges for the next century.

Note: There is another article about the .375 Ruger on the Rifle Cartridge Page.

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Copyright 2007, 2016 by Rick Ryals. All rights reserved.