"----------how are vent ribs functional on a shotgun?"

My best recollection, from a looooooooong time ago: They dissipate heat, thereby preventing/mitigating "heat waves" that otherwise interfere with your vision.

Now we clearly are not talking about tromping around in the weeds after the occasional poor defenseless little rabbit, but rather standing on our hind legs whammity-bamming A BUNCH of poor defenseless clay birds in competition on a skeet/trap field, or sporting clays course.

That said, and while I had several shotguns with vent ribs, I never shot them in any sort of competition except against friends and neighbors out in the front field----where there was more flab-gabbing than shooting going on.

There are those who will tell you the nice, flat top of the rib makes for a helpful aid in aiming. I will tell you if you've made the effort to have your shotguns fit to you, and to mount your gun the exact, same way EVERY time, there's no aiming going on----just seeing. And what you see is what you hit---each and every shot! It almost gets monotonous----almost.

My first experience---WAY back when, with my first shotgun (Browning Auto 5) was an eye opener!! Now I clearly had a BIG advantage, because my gunsmith's day job was as "the wood guy" at Browning's faciiity in the St. Louis area. So here we are in his shop. I'm in one corner, he's in the diagonal opposite corner----a good ways off. "Shoot me in the eye!", says he. I do just that---several times. He then takes my BRAND NEW shotgun over to a belt sander, and GGGGGGGRRRRRRRRIIIIIIIIIIIINNNNNNDDDDDDDDDDSSSSSSS on top of the stock!!!! I was properly horrified, but I was over it after the fourth or fifth repetition, when he asked, "Do you want a recoil pad on it?" I did. "I'll call you when it's ready." He did.

I have NEVER missed with that gun----NEVER!! The bad news is your friends will come to hate you before your very next hunting trip is even half over. You'll get so you let them shoot first (and miss), before you take your shot.

Ralph Tremaine