You should not sweat flippers and spinners as it is part of hunting.
Hunting predator calling competitions years ago, we learned from the old timers that started calling in the 50's not to wait for standing shots only. They would chew our azzes out for not taking a shot on a walking coyote. Marginal hits were not unusual as we learned how much to leade the animal and shots too far forward, too far to the rear were common. Put them on the ground and hit them again. It was a heck of a lot better to miss than to let one walk off. We could not win competitions by not shooting.
Our all time high was 59 animals in a 48 hour hunt. One year, we turned in 32 animals and got third place.
Speed and bullet choice does make a difference on marginal hits. A bullet that penetrates well with speed will give a guy better odds.
It seems politically correct these days to only shoot at standing animals. Be Bold, learn to Leade coyotes and kill coyotes on the walk, then the trot. An all out grey hound running animal is a hail mary shot, but I have known two hunters that were darn good at hitting coyotes on a dead run, they have both passed on.
A guy that has some experience with a shotgun shooting quail, doves can learn to leade walking and trotting coyotes with amazing success, just do not be afraid to fail, missing is part of hunting.
As your impact velocity goes down, so does the size of the temporary wound cavity that your bullet makes with less arteries and nerves severed. It is fun to play with different guns and bullets over your hunting career and constantly tune your likes and dislikes based on your own personal experience.
Gun fit and a gun that swings easily are my favorites. Ar's do not fit me, and in the calibers I like they are way too heavy...to each his own.
In my Remingtons, Ruger 223 sporters, I like a 55g Sierra lead tip blitz at 3400 using a hot load of benchmark which blows a coyote up. In the 22/250s, I like a 55g Sierra of sorts in front of Varget which puts me in the 3750 fps area. In the 243's, I like the 55g Nosler(4000 fps, 60g Sierra(3800), 80g sierra single shot pistol bullet or blitz bt(3400). The 6 Remington is a monster, 60g at 4000, and 80g at 3600. The 6AI Big brother, 60g at 4400, 70g at 4000-4150, and 80g at 3800.
Speed give a guy more confidence as you have less leade as the distance increases and a much larger temporary wound cavity when you connect. Impact velocity turns bones, tendons, stomach contents into secondary projectiles.
Few people ever consider the 270 winchester with a 90g Sierra at 3550 or the 110g Vmax at 3350, but this is one heck of a coyote rifle. This is probably the mack daddy coyote rifle on a budget, very, very accurate with the light bullets and will shoot the entire azz end off a coyote if you don't leade the animal enough.
25/06's were very popular on our team for a few years, till the barrels were shot out. 100g Sierra at 3200 or a 87g sierra or Speer do not leade to coyote run offs very often at all. Hides were not worth saving at this point. You rarely ever hear of anyone shooting a 25/06 on predators anymore...what a shame.
As we see the marketing trends, short barrels are the rage, now throw in heavy bullets, and the size of the temporary wound cavities goes way down. This will cause a lot of spinners as range goes over 200 yards. We did not see a lot of spinners with the 22/250 shooting the 55g Sierra at 3600 till the range got to 250 yards, and that is where we started getting picky on the shots. We usually hunted four guys in the truck, and we learned that the guys with 243's had an edge at 300 + yards. I had a custom 6 Remington and another AI that were our Nevada guns where the coyotes would hang up around 400-500 because they were so call wise, and the 80g Sierra at 3600 would put them down hard.
For guys that have the mind set to only shoot at standing coyotes, try this. ON a walking coyote at 100 yards, put the cross hair on the leading edge of the coyote. Remember that if the coyote is coming down hill, you will have to aim at the bottom of the body. ON a trotting coyote at 100 yards, try aiming 1.5 feet in front of the animal, and if the animal is at a fast walk, aim 3 feet in front of the animal. Remember, it is better to shoot and miss than let him run off, because the coyote is a genius at putting any and everything he can in front of you and him, using every bush, dip, and rock. If you stop your swing and do not follow through, you will shoot behind the coyote every time. Shooting skeet really helps a guy improve his follow through and have confidence in leading an moving animal.
Also, know your wind direction. If a coyote is approaching your scent cone down wind, you have to take him before he picks up that scent, or he is GONE! If you see a coyote approaching your your tracks that you walked in on, take the shot.
Above all, don't sweat the nippers and spinners, it is part of hunting. Don't be scared to try different bullets, different calibers and enjoy the learning process.