Ithaca 37s and Winchester Model 12s are made to be pump fired.
That is why Military, Prison Guards and Law Enforcement always wanted these shotgun.
I do not know who invented the Winchester Model 12.
John Browning designed the Ithaca Model 37 if you look up your history before the patent was sold.
The gun was designed to fire that way.
Ithaca took that off their shotguns in 1975 I guess the people at Ithaca in 1975 thought they were smarter than John Browning who designed that shotgun.
I have 3 Ithaca model 37s one 12 gauge made in 1947 that my uncle left me in great condition and two that I bought new in 1967 one in 12 gauge one in 20 gauge.
All of them have had thousands of rounds out of them all look and work great.
All have been slam fired plenty with no problems at all.
Fred