>>7987818If you don't mind pumping up an air tank for a bunch of semi-auto shots, you have a pretty good amount of options.
If you want pure no-priming double action semi auto, your options are
>>7987823 or finding an old dart tag snapfire which worked the same way. That one's a lot smaller and it's also neat because it has a power adjuster you can tighten or loosen to choose a balance between dart velocity and trigger weight.