Steel-Cased 7.62x39 mm In Ruger Mini Thirtys?

by
posted on June 25, 2014
** When you buy products through the links on our site, we may earn a commission that supports NRA's mission to protect, preserve and defend the Second Amendment. **
mini30F.jpg

Q: I’ve been shooting Russian-made 7.62x39 mm ammunition in my Ruger Mini Thirty. The steel cases are coated in some sort of lacquer for corrosion protection, which I think has been causing rounds to get stuck in the chamber. My brother has had similar issues, and he said the lacquer is causing a residue that is very difficult to remove-even after a thorough cleaning. Anyhow, I believe that this cheap ammunition is a failed product that is being offered and that NRA members should be made aware of the issues.

A: Thank you very much for your question concerning functioning issues of steel-cased ammunition in your Ruger Mini Thirty rifle. This is a sensitive, and sometimes emotional, subject for a number of 7.62x39 mm shooters. Needless to say, proper, efficient, and accurate functioning of firearms, especially autoloaders, requires that the firearm and ammunition “mesh.” In other words, the maker of the firearm and the maker of the ammunition must know and appreciate the dimensional and performance standards of the other party. It would do neither of them any good to design and develop their products in total isolation. That would represent not only bad business practice, but also lack of concern for consumer satisfaction, not to mention consumer safety.

That is but one reason for the existence of Sporting Arms and Ammunition Manufacturers Institute (SAAMI). Membership in SAAMI is voluntary, but essentially involves the agreement to produce products that will safely fit and function with other members’ products. The key word is “tolerance.” The tolerances allowed are close, but permit the manufacturers a degree of choice in design.

The 7.62x39 mm is an active SAAMI cartridge. One of the several cartridge “features” defined by SAAMI concerns chamber pressure produced. The means by which this property is measured requires a brass case, which immediately precludes steel-cased ammunition.

To get Ruger’s perspective, I contacted a member of the company’s service department. He was quite familiar with your concern, and also mentioned issues of extractor breakage and debris from the case coating fouling the firing pin and gas system, and that the ammunition is not to SAAMI specification. Ruger’s official comment regarding ammunition is, “Only factory ammunition manufactured to U.S. Industry Standards should be used in a Ruger firearm.”

That begs the question of why the same ammunition usually works fine in SKS and AK firearms? (Note that neither guns nor ammunition are produced to SAAMI specs.) The answer goes back to tolerance and design features of the firearm makers. Those rifles and their chambering were designed for infantry use. In such cases, accuracy is important, but reliability is paramount. The Ruger will deliver significantly better accuracy and can be utterly reliable, but it will require that the ammunition used be constructed with the same attention to specifications as the firearm.

-John W. Treakle

Latest

bluing with torch
bluing with torch

Tips & Techniques: DIY Fire Bluing

Is there anything prettier than fire bluing? This bright, “peacock” blue color is one of the world’s oldest firearm finishes and can be found on guns dating back as early as the 16th century and is still used on some of today’s high-end custom arms.

Rifleman Q&A: Eddystone Bayonets

"I recently started collecting World War I U.S. military firearms. I want to obtain a Model 1917 rifle made by each contractor—Winchester, Remington and Eddystone—along with bayonets for each. However, I can only locate bayonets made by Winchester and Remington. Why are bayonets made by Eddystone so hard to find?"

NRA Youth Education Summit 2025 Provides Scholarships, Leadership Lessons

The 2025 NRA Youth Education Summit (Y.E.S.) brought together 32 exceptional high school students from across the United States.

Unfair Advantage: The Walther PDP Pro-X PMM

The latest “Pro” model in this famous German maker’s line of U.S.-assembled pistols leverages more than 100 years of experience in building service-size semi-automatics. And the results are better than even most experienced shooters should expect.

The Armed Citizen® Sept. 8, 2025

Read today's "The Armed Citizen" entry for real stories of law-abiding citizens, past and present, who used their firearms to save lives.

Terminal Ballistics 101: What You Must Know As A Rifleman

It is easy to take a box of bullets for granted, but as a rifleman, it is important to understand all variables at play when it comes to terminal ballistics. This guide, from NRA Firearms Sourcebook, will help drill down on what is important.

Interests



Get the best of American Rifleman delivered to your inbox.