I have been thinking about making a pump action AR pistol for a while. There is still one company that makes a kit but I though maybe I could make one myself, but then I had another idea that would be an alternative to a pump or bolt action AR15.
So here is my idea, and tell me whether you think it is different enough that it couldn't be considered semi-auto.
Normally the bolt catch only activates after the last round with an empty mag, but imagine a bolt catch that holds the bolt open every time you fire. So fire a round and the bolt goes back but it stays there. Then you have to push another lever or button to release the bolt back forward. Then you can pull the trigger again. Technically this isn't semi auto as I understand it but maybe I am missing something? As long as you have to perform another action before you can fire again then it isn't semi auto right?
This way you could have an AR-15 rifle that could work in California or an AR pistol in Hawaii that would be legal and it could be fired relatively quickly, quicker than even a pump action AR.
Trying to figure out how to go about accomplishing this mechanically though. I could just put a spring on the bolt catch so it always activates but if it were that easy to drop in I think firearms would see it as still semi-auto since it could be taken out so easily.