This is a post in response to some confusion out there about the A1 setup-
the A1 upper comes in a lot of different configurations.
I have a Colt SP1 made in '76- A1 upper with NO shell deflector, NO forward assist and the old style A1 sights. This is a true "slab-side".
I have a early 80's SP1- it also has the A1 upper with NO shell deflector- but this one DOES HAVE a forward assist (with the round knob), and the old style A1 sights.
I have another A1- this one's a Bushmaster M4gery with a requested A1 upper- this A1 DOES HAVE a shell deflector, and it DOES HAVE a forward assist (with a tear-drop shaped knob), and the old style A1 sights.

Three different rifles, three different configurations, ALL CONSIDERED A1 UPPERS.

If you're confused don't feel bad- it's confuzing!!!