There are 2 a1 uppers but no a2?
What gives? Licensing?
If it could be added that would be cool. Also maybe add why something wouldn’t work.
I had an A1 upper with a rail that would not work for some reason?
Probably has something to do with not being a flattop upper though.
Interesting... I'd never thought about it until now, but "how come" actually makes no sense.