Once the shooting starts over the bait, it will be anybody's guess as to if or when they will come back. IF you can use a bow that would be a good start especially if you have seveal folks who hunt archery. It will allow you to get more shots on more hogs before they figure out the jig is up. IF you hit one and they scatter with mot much other noise they will usually come right back. If you can use the times feeders by all means do so but also look into the hog lights which are so popular. Once they get accustomed to them they will come right on in.
If by no center fire rifle, and your allowed shotguns, I would go after them using an open choke and buck shot. Be sure to pattern it to see whee the best coverage will be. This will allow you to set up right on the max spread and be able to possibly get as many as possible with the least amount of shots.
When they get up under a feeder like this,
a good load of 00 does a great job of thinning them out pretty quickly. This is why I said to check your pattern, if you know how and where to put them you maximize your shot, especially if your elevated so you can get more concentration on individuals rather than relying on pass throughs. A two person bow stand or platform with two of you using the same loads would knock out a bunch with one salvo. You might have to track a few down for a finisher but you would be guaranteed at least 4-6 on the ground depending on your load.