Got the 4-jaw indexing head chuck mounted - works great! (Pic didn't turn out).

Completed rotary milling the front sight band with 1/8" long end mill.
Faced off muzzle, cut crown. Mounted front sight band on barrel; mounted barrel on barrel extension ['receiver'] for pics. Also made up a special 'keyhole' spanner for mounting/removing the front sight band. Thread is 1/2" x 28tpi, same as M16/AR-15 barrel/flash hider.
Hard to photograph bright shiny objects in the shop.