Honestly, for all the expense of engineering a manual action handle on the wrong end of the operating rod, what's a few dollars more to let the gas work the action? Pumps are everything except a piston and cylinder.
For all the guys with sharp sticks poking around about "spray and pray," you'll find an equal number of filled magazines and one extra topped off in the chamber. I've NEVER met a hunter in a parking area, or read in a post, that loads one bullet at a time only when the rifle can hold more.
I HAVE heard the bolt, lever, and pump hunters in the woods around me cranking off rounds as fast as they can work the action. Considering they don't even go to the range every month, and when they do, NEVER practice the technique, how accurate can they be? Especially bolt gunners taking their hand off the trigger every time?
It's been my experience that if you do want to take another shot, the semi auto allows the hunter a better and more easily acquired, more accurate second shot. The hands never get moved off the controls - he simply recovers from recoil, resights, and decides. No jacking the action while the jumping deer bounds off into the cover. And does it with a typically restricted mag of 5 to 10 rounds, about the same as those fully loaded and topped off manual actions I hear blazing away every year.
The myth of the ethical Great White Boltgunner only taking one shot must be getting acted out over a cleared lane 50m from a bait pile.
In that regard, why even have a magazine fed rifle? A single shot would do, much less a pump.
