First of all, I've been using my 870 with rifled barrel / rifled sights for about 5 years with good success on deer. I'm 4/4 with it.

For accuracy, at the 100 yard range, I can hit a 9" paper plate consistently with 3" Winchester Hi-Impact Supreme sabots. The setup kicks like a mule, so "consistently" should be read as "the first couple of shots".

In my opinion, this 870 with rifled pipe is way overkill for `yotes. I have had pass-throughs on all deer I have taken with my gun ranging from broad-side to quartering away shots. A guy that I work with that has actually hunted coyotes swears by OO Buck from his 12 ga out to about 50 yards.

Personally, I would choose a rifle. Decent sabot slugs are about $2/each. I have shot standard "rifled" slugs through the barrel out to 50 yards and they seem to stabilize and hit the point of aim fairly well - almost as well as the sabots. The drawback is that they are less aerodynamic and will drop faster as range increases - so at 100 yards you might be a lot lower than a sabot through the same gun.

For a rifle, I wouldn't go less than a 222 or 223. A 243 would be better (and could double as a deer rifle).