This seems to be a Browning design/feature, as it shows up commonly on Browning designed guns. The model 12 is not a Browning design, of course, but Winchester's designers used a lot of the Browning ideas on it, like the takedown method. This function is also from another time, when shooters were expected to be smart enough to not hold the trigger as they closed the bolt on a pump gun UNLESS they wanted to fire it again very quickly. Holding the trigger back while pumping the slide is about as bright as holding the trigger while cocking the hammer, on a hammer gun. You really need to be smarter than the gun. I rather expect Herb Parsons used this feature to his advantage when breaking 7 hand tossed clays with a Model 12 pump.
Nowadays, everyone seems to feel the need to be protected from every possible mistake, so disconnectors have been added to pumps, automatic safeties added to SxS, O/Us, even lever actions and hammer guns, fercrysakes! How long before we add automatic safeties to semi-automatics?
