I came across a M. 80 Mossberg 410 BA shotgun a while back. Seems that this was the first BA 410 that Mossberg made-sometime in the early 30's. This one needed a bolt cocking knob and had no luck in finding one. It was clip fed and chambered in 2 1/2 in. I tried all the main parts houses. Any info about parts would be appreciated. Hunman55