Some shotguns were designed that way. The model 12 and the model 37 are two I know of. They both have a "disconnector" that is timed so the hammer will not fall before the bolt is locked. The model 97 and the model 12 when worn or when someone alters it (not knowing what they are really doing) often will drop the hammer when the bolt is open. The thing to check is will the hammer release before the bolt is in the fully locked position. Hold the trigger in the fired position, and very slowly close the action, just inch the pump ahead as slow as possible, note if the hammer falls before or after the bolt locks up. If the hammer drops before the bolt is locked up, fortunately there is another "safety" design in the model 12, a firing pin block that blocks the firing pin from protruding if the bolt is not locked up.
The Winchester 1200 series has always felt scary to me. Some of them will actually fly back on firing and eject the shell...... that has to do with the rotary bolt and the smoothness of it... it is still safe, that is also part of the design ....
It is harder to hit anything you are trying to hit when you slam fire..... even a target at a few feet is easily missed.