I split the piece of firewood today and found 2 boolits. One made 6-1/4" and the other made 6-3/4".
Elm is very tough and wood was welded to the boolits.
The .475 made 16" of oak so with elm you just can't compare penetration.
It took a lot of hits with a sledge hammer and an axe to open this piece of wood.
It has to be one tremendous amount of power to get this deep with that large of a boolit.

Damn impressive, Jim!

The 525 grain load at 1100 FPS is a very impressive load especialy on game

and the bullets didn't deform???

That really is hard cast.

I know how hard elm is and this is pretty impressive.

Elm wood was valued for its interlocking grain, and consequent resistance to splitting, with significant uses in wheels, chair seats and coffins. The density of the wood varies due to differences between species, but averages around 560kg per cubic metre[11]. The wood is also resistant to decay when permanently wet, and hollowed trunks were widely used as water pipes during the medieval period in Europe. However this resistance to decay in water does not extend to ground contact[12].

That load is a hammer!

Wonder why elm isn't more popular for grips for heavy recoiling handguns???