I have never cared for cheek rests on a shotgun. It is my belief that, even on a rifle, they are there mostly for aesthetics. They perform no basic function that cannot be achieved with a properly designed buttstock which does NOT have a cheek rest.
I can not comment regarding more modern rifles, but I can say with some conviction that that does NOT apply to period flintlocks. The cheek rest on a period flintlock serves a purpose and is very comfortable to shoot compared to one without. However, and this could be significant, the cheek rest on late 18th early 19th century flint rifles were not designed like that that we commonly see on more modern rifles. They are concave and tend to roll UNDER the cheek rather than just pushing the cheek out. For many years I built period flinters and would never dream of making one without the period correct cheek rest. Interestingly, even then, cheek rests were not common on shotguns though. It is also noteworthy that these same flint rifles that pretty much ALWAYS sported a cheek rest also were made with cast, 1/4" being not unusual, something I don't think is all that common on rifles of more recent vintage. For the record, I also do not care for a cheek rest of any kind on a shotgun.
