He was a Lone and Angry Man
The mysterious Shenandoah (Anthony Steffen) shows up in town and comes to the attention of a ruthless bunch of outlaws not just because he carries a huge wad of cash but also because he can clearly handle himself. After passing an initiation test which puts him close to dying he joins the gang. But after a while the other members of the gang start to question his motives and suspect he is a traitor with another reason for joining them.
Let me cut to the chase; the mysterious Shendandoah is in fact an undercover lawman by the name of Joe Logan and as is the usual case he has gotten himself on the inside to try and capture the bad guys but ends up in trouble when others don't trust him. This is the sort of storyline which 20 and 30 years earlier would have been doing the rounds between the western stars of the era. It means that whilst "A Coffin for the Sheriff" has more time spent on the story than those 60 minute westerns of the 40s would have it is for the most familiar, although the initiation test s straight out of a kids imaginary game.
But of course there is something else which makes "A Coffin for the Sheriff" different to those westerns of the 30s and 40s which is of course this being a spaghetti western. Sadly as spaghetti westerns go this one is extremely ordinary with no great styling or music to make it memorable. In fact as memorable things go you are more likely to remember the dodgy dubbing rather than anything else.
What this all boils down to is that "A Coffin for the Sheriff" is just about an average spaghetti western at best with a routine storyline, routine characters and to crown it off routine styling which make it all routinely forgettable.