The following graphic presentation compares barrel heating that occurred in each barrel as easured at each indicated location and in terms of degrees centigrade temperature increase. Note apparent anomalies in several of these curves suggesting slower cooling toward muzzle end; we have no good explanation for this but we certainly cannot rule out experimental error. Since barrel damage from overheating is never seen toward muzzle end of a bore, we can reasonably assume that any such measurement errors that may have occurred at the 24-inch point are not all that meaningful – what matters most is barrel heating over and immediately forward of chamber!
Refer to the following graph: Evident increased cooling rate at chamber end results from heat loss into receiver. Remember that we had fired twenty shots, at a cadence of fifteen-seconds per shot, before this data was taken. Hence, during interval between firing first shot and firing last shot, sufficient time passed for considerable heat to pass into receiver.
Note that the 5/35 (curves marked with squares) generally produced barrel heating that was similar to heating produced by both the 223 Remington (curve marked with diamonds) and the 204 Ruger (curves marked with triangles). This was the result, despite a massive performance advantage for the 5/35. Not surprisingly, the 22-250 Remington (curve marked with circles) generated dramatically more barrel heating than any other tested load.