E,
One of the clubs that had the worst problem was the (now defunct) FW R&P. At the Hunter's Pistol Nationals there several people were injured. Many more were struck. Although the worst of it was during the centerfire, it happened during smallbore as well. In my *opinion* the difference in the way the HP animal reacts (because of its mass) is a factor which probably contributes to the problem of back splatter off of the animals more than with smallbore rifle animals, but it was coming off of the rails as well. Not only were people on the firing line struck, but people behind the firing line.
I have observed back splatter elsewhere on an occasional basis. Part of the difference between club matches and larger matches is that the firing line is typically crowded at larger matches, meaning that anything which comes back at the right height is probably going to hit someone, and there is more lead going downrange.
I have not kept up with which ranges are more troublesome than others, but the potential for back splatter is there no matter what the circumstance. "Protecting" the rails simply reduces the likelihood of it occurring (by a substantial amount in my opinion).
Chunter is wise to ask the question. It is best to do what he can to reduce the probability of it occurring from the outset and to do what can reasonably be done to reduce the chances of a serious injury (as in eyes) by requiring the wearing of eye protection.
The NRA has planted their heads in the sand over this issue for a great many years, despite the fact that IHMSA (by national rule) requires the wearing of eye protection. By the way, each and every IHMSA club and event is covered by NRA's insurance program as they join for that express purpose so don't be fooled by the people at the NRA or on the Silhouette committee crying wolf about lawyers and so on and yada, yada, yada. The silhouette committee did not understand the matter then (even when confronted by a competitor who had been struck in by a piece of bullet over the pupil of his (dominant) shooting eye which left a "nick" in the lens . He said "I would be blind in this eye right now if I had not been wearing shooting glasses") and probably does not to this day.
How important is one's vision?
I am not questioning your belief that your club does not have a problem in asking this question, but how do you actually know that you do not have back splatter? Is it that no one has reported being struck? That does not necessarily mean that it is not happening.
Under the right circumstances it can happen and so I believe that Chunter's question and the precautions he is likely to implement are, in my opinion, worth the small effort when weighed against the potential consequences of the one that has everything go wrong in the right sequence.
As you may recall, a fine young man was killed in the metroplex (at the Dallas R&P if I recall correctly) at a sanctioned pistol match because people failed to follow their own rules and were aware of the problem that resulted in his death.
Safety requires constant vigilance.
You will have to judge the suitability of the precautions taken at your range.
Regards