Yesterday 8:27 am
That doesn't answer the question...it just debunks your fiction.*Huey » 2 minutes ago » wrote: ↑ You have seen this many times before:
To prevent a civilian semi-automatic AR-15 from being readily converted for use with the select fire components, several features were changed. Parts changed include the lower receiver, bolt carrier, hammer, trigger, disconnector, and safety/mode selector. The semi-automatic bolt carrier has a longer lightening slot to prevent the bolt's engagement with an automatic sear. Due to a decrease in mass, the buffer spring is heavier. On the select-fire version, the hammer has an extra spur which interacts with the additional auto-sear that holds it back until the bolt carrier group is fully in battery, when the automatic fire is selected.[76] Using a portion of the select fire parts in a semi-automatic rifle will not enable a select fire option (this requires a registered part with the ATF). Lower receivers that are select-fire are identified by a pinhole above the safety/mode selection switch.[77][78][79][80] As designed by Colt, the pins supporting the semi-auto trigger and hammer in the lower receiver are larger than those used in the military rifle to prevent interchangeability between semi-automatic and select-fire components. The pivot pin may also be slightly larger in diameter.[81][82]
https://en.wikipedia.org/wiki/AR-15%E2%80%93style_rifle#:~:text=To%20prevent%20a,%5B82%5D