In article , "Thomas J. Paladino
Jr." wrote:

snipped
(Knew most of this)

All shooting ranges in the US (and NATO) have stopped using heavy-metals in
all of their training rounds (including small arms). DU was never used as a
training round to begin with because it is too valuable. The M1 sabot
practice round uses a steel core and behaves exactly as the live round
would.

Interesting. As a re-loader, I'm curious how a steel core replicates the
sectional density and ballistic coefficient of DU and therefore the ballistics
of the round? After all, DU is about 2.33 times the density of steel (I used
values for Maraging steel, but 300 series is the same, and higher than
alloy steels), so to keep the same mass the round must be bigger,
but that would degrade it's areodynamics.
Can you elucidate? I don't understand.

--
Harry Andreas
Engineering raconteur