The Slide Fire stock is designed to convert a semi-automatic rifle to perform like an automatic rifle, period. No, it does not operate like an auto sear, but it is designed solely and exclusively to make the weapon operate like a machinegun. That the designer used a different approach to achieve the high rate of fire is not going to matter to a judge.
As I said earlier in this thread, I think automatic rifles should be legal, but that is not the law. This EO is following the spirit, if not the letter of the law.
We disagree. Bump or slide fire in your words "does not operate like an auto sear", so it does not convert a semi-automatic into a machinegun. Mimicking the rate of fire of a machinegun is not the same as converting into a machinegun, which by definition fires more than one shot by a single operation of the trigger. As a citizen, I follow the spirit of those laws that have legitimacy, but a judge or a government official has only the authority to enforce the letter of the law. If a law is poorly worded, the proper remedy is legislation, not reinterpretation.