Civil rights victory,

also a big slap at "We don't have to go through Congress to make law":
Today another federal court rejected President Joe Biden’s war on guns, ruling against his effort to require 3 million to 7 million owners of AR-style pistols to register and pay a $200 tax on their firearms or face prison.

In the latest blow to liberal gun control politicians and the Bureau of Alcohol, Tobacco, Firearms and Explosives, the St. Louis-based 8th U.S. Circuit Court of Appeals rejected the government’s plan, claiming it was likely to get tossed by the Supreme Court.

For now, the millions of users of guns equipped with “pistol braces” can keep them without fear of being fined or jailed.
...
The court said the ATF rule was poorly written and vague and gave the agency too much leeway to go after owners of the popular firearms.

“The final rule, as a whole, is arbitrary and capricious because it allows the ATF to arrive at whatever conclusion it wishes without ‘adequately explain[ing] the standard on which its decision is based,’” said the court.

“This is much like shooting the side of a barn, drawing the target around the bullet holes, and then proclaiming, ‘Bullseye!”’ added a footnote in the decision that sent the case back to the District Court.

The ATF ruling was also rapped for putting the burden on gun owners to prove why their guns would be allowed. The court said that was wrong and it is up to ATF to better provide guidelines. “The ATF’s burden-inverting argument makes as much sense as shouldering a rifle by the barrel,” mocked the court.
Which also tells Biden, Harris & Co.- again- that they can't just do whatever they want.