I once belonged to a gun club where one of the members brought out a steel manhole cover and left is at the 200 yard berm for other members to shoot at and try to penetrate. I tried all the heavy calibers I owned at the time, including .375 H&H, .416/.300 Winchester Magnum and .458, using solids, and achieved little or no penetration, but some impressive cratering.

Then I tried a handload consisting of a US made 165 grain armor piercing bullet in my .300 H&H, and it went through the metal like a knife through hot butter. I expect the original .30-'06 AP load would have done the same. I have read all the accounts of double rifles in the trenches, and I am afraid I viewed them with great scepticism, based on my own experience.

Years earlier, a German friend of mine had invited me to hunt with him on what had been a Bundeswehr firing range near Stuttgart. As we were leaving after an unsuccessful hunt, we came upon an abandoned armored personnel carrier which had been used as a target. Out of curiosity, I fired a round from my friends 8X57JS hunting rifle at the armor plate.

When we examined the plate, it was only with difficulty that we were able to determine where the bullet had hit, so little impression had it made on the armor plate. In fact, if the plate had not been painted, we probably could not have determined the point of impact at all.