I think there are a couple of areas not being taken into account.

Woodleigh Bullets made for doubles rifles are tapered
(as were the original kynochs) so that a .458 bullet
is not .458 along the whole shank, only the first part
so regardless of how hard it is, it decreases pressure.

Also, Woodleigh's are designed for hunting DG which
is why they are made how they are - I am sure you prefer
the confidence of standing in front of an Elephant with a
Woodleigh Solid or Soft Nose over a Hornady Solid and
Soft Nose.

I have shot solids and soft through over 20 of my own DR's
and never had a problem including DR's with tight bores (.408)
and in guns from 1890 - 2000. I would not do it if I thought
there was a slight chance of possible damage.

Just my HO.

500 Nitro