Well, let's see: I've been carrying a sporterized Springfield '03 with Williams peep rear and bead front sight for some years. Only had success the very first year I took it hunting, in which I muffed my pistol shot(s), and had to drop the running doe with a shot to the head at about 80 yds.
This year I passed up a shot at three doe at about 100 yds with it (now reincarnated as a .35 Whelen), because it was foggy and just too dim at the crack of dawn.
I've shot a hog with an iron-sighted M94 Trapper.
I've shot 2 javelina (in one episode) with an iron sighted Officer's Model Special .38 Spl, and one with my duty gun, a Kimber Stainless Classic 1911.
I've carried a SMLE #5 Jungle Carbine with 180g GameKing handloads while hunting elk in the black timber, but never got a shot. Factory rear sight, brass bead on post front sight.
I've carried a SMLE #4 Mk I while hunting deer, and passed up an easy 40 yard shot on a spike one cold morning. Factory peep rear and post front sight. Had he come another 20 yards closer, I would probably have shot him with my iron-sighted Colt Gold Cup, which I was carrying that day.
I carried a Remington 1100 with slugs and open Brownell's sights screwed onto the vent rib during one weekend game management hunt in San Angelo's O.C. Fisher State Park. They wouldn't allow any firearms other than shotguns with slugs or muzzle loaders, due to the proximity to the city. I passed up a couple of 90 yard shots, because that was the OUTER limits of what I was comfortable with trying to make with those sights (coarse) and that trigger (coarse).
Last coupla years, I've been seriously looking for a deer to come within my 25 yard radius while carrying a modified 4.5" Super Blackhawk .44 Mag with SWC handloads. So far, have only used it for a
coup de grace on one big buck that I shot with a Sendereo.