BTW, you can get a mosin nagant for less than $100 on several different websites. it's not that common a caliber and i wouldnt trust it past 100 yards, but you'd kill a coyote dead with it.
Depending on how worn they are they are capable well past that. I have gun magazine where they were shooting a 16" group at 1000 yards using a period correct PU scope. Not wonderfully great but still noteworthy on a 60 year old surplus rifle with a 3x scope.
Around here both Cabela's and Sheels stock bullets, for a little bit Cabela's had fancy Hornaday polymer tipped cartridges... I hope it was a feeler and they get more in because I really liked the concept.
My 1943 Ex-sniper was $100 with the tool kit and bayonet. I stuck a 2x6 pistol scope on it with a Darrel's mount and got a plastic stock to cut down on the weight. At 80yds (as far as my range is) I can do a fairly decent job keeping the holes touching. It has been a fun project but for about the same money I could have gotten an entry level rifle with a scope that shot more common amunition. With the original sights I could outshoot it with my 20ga shotgun with a $80 smooth slug barrel with rifle sights. That thick sight pin covered up the whole paper and it shot way high. I have read they were trained to use the belt buckle as a common sight referance and then the bullet which would put the bullet in the vitals. Since deer don't wear belts that didn't do me much good...
In my younger years I did sneek up well within slug range (less than 100yds) of coyotes while I was deer hunting (only shotguns are allowed in Iowa during antlered seasons) and taken a couple potshots for the heck of it, they are a small target and never seem to stand still. Later on I realised that shooting at them with my thumper didn't do my deer hunting game any good so I quit.
I have heard of people getting rifled chokes, it still has the same sound of the gun going off and then a weird thump sound as the gun farts out the slug that using more open chokes have. I am kind of leary of them and can't see where it would do the threads much good. H&R Pardner single shot shotguns are pretty cheap too, I would almost rather do that than pound on my Benelli barrel (if I had a Benelli) It would be hard to be very accurate at any kind of a range without rifle sights. 100-150 yds is about it with a rifled slug in a slug barrel, I prefer Breneke slugs which work in either smooth or rifled barrels.