Although CW use of whitworth bullets was relatively rare, suspect that a fair proportion of fired rounds missed targets, with some of these failing to make any impact. Thought there would certainly be some spent projectiles (that failed to impact) to recover on the ground. (I myself, have a large collection of many fired and some dropped cylindricals, as well as a few dropped solid hexagonals from the era, but no fired hexagonals - believe anyone who found a fired CW battlefield authenticated hex would possess a very valuable wartime relic, at least to a collector).