A federal judge has decided that 7N6 ammunition—favored by many AK-74 rifle fans due to its low cost—is indeed “armor-piercing” under federal law and cannot be imported.

A federal judge in Seattle has upheld a decision by the federal Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) to ban ammunition originally designed for AK-74 assault rifles.

The decision Wednesday by U.S. District Judge John C. Coughenour came in a lawsuit brought by Redmond-based P.W. Arms Inc., which obtained permits to import more than 100 million rounds of the Russian- and Eastern European-made ammunition known as 7N6. When the first shipments arrived in early 2014, the ATF deemed them “armor-piercing” and barred their importation for civilian resale.

The company said the agency misinterpreted the definition of armor-piercing bullets under federal law. But the judge disagreed, saying they contain a steel core and can be fired from a handgun.

The “handguns” in question, of course, are stockless AK-74s. They don’t fit any rational definition of a handgun, but are considered handguns because of our frankly bizarre and sometimes nonsensical gun laws. 5.45×39 pistols like this Arsenal AK-74 pistol listed on Armslist several years are very few and far between.

This decision will result in PW Arms not being able to sell the 100 million rounds of 7N6 ammunition they acquired on the U.S. market.

This may be less of an practical issue than some people think it is, however.

7N6 was the original load for the AK74, but wasn’t the the best and the Russians began phasing it out in 1987 in favor of improved cartridges. As a practical matter, the retired 7N6 supply was already beginning to dry up.

Commercial manufacturers such as Barnual, Tula, and Wolf stepped into the gap left by the fading 7N6 supply long ago, and 5.45×39 FMJ loads are easy to find online to keep 5.45×39 guns fed and happy. Hornady has even stepped up with polymer-tipped varmint hunting load.

7.62×39 ammunition is a few cents a round cheaper than 5.45×39 simply based on the fact that there are more manufacturers and higher demand driving the prices down, but 5.45×39 supplies aren’t going to dry up.