Any sense in doing this?

You’re instinct is dead on and your friend is wrong. Down-shifting (usually for trucks)is done for encounters with rough or steep grades. His manual TX will probably handle it, but there are a whole bunch of other parts in the chain that won’t.

Around here I kid you not,these guys use .338 magnums on little ol whitetail deer.(betcha been more taken with 30-30s than any other centerfire)-Kevin