I recall reading about shot being "pressure welded" together into a clump while traveling down the barrel, presumably because they bridged across the bore, maybe due to some interference from the wad or crimp. One issue is that these clumps can travel well beyond the normal shotdrop zones and cause injuries.
Ruag This is the greatest possible hazard with a favourable firing angle. This hazard area is significantly lower for soft iron shot because of the lower specific weight of the shot. Clumping shot however forms projectiles of greater weight and therefore, depending on the weight of the shot lumps, can endanger the surroundings at significantly greater distances.
Perhaps it could have happened when the shells were made. I would think it would only take 2-3 fused 7.5s to decapitate a dove.
And a single pellet might be enough to do the job - at 25 yards, a 7.5 pellet shot at 1295 fps retains over 2 fpe. If properly placed (a task you are clearly capable of
), I would think that could be enough energy to do the trick. I shot a preserve cock pheasant in the neck a few years ago and nearly decapitated it.
