"Harry Andreas" wrote in message
...
In article , "Kevin Brooks"
wrote:

"Harry Andreas" wrote in message
...
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.

It does not have to. When firing the training rounds from the M1A1, the
ballistic computer is set for the APDS training round, just as it is set
differently for the HEAT round vice the DU APDS-FS--the computer adjusts
the
aim point accordingly.

Just so.

Maybe I didn't snip enough, but he said, "exactly as the live round
would."
That's what I was questioning.

Frankly, I would expect a change in ballistic performance, culminating
in an adjustment of the sights.

You are probably right, hence the different settings of the ballistic
computer. I guess you could develop a matching training round if you really
wanted to; the lighter composition of the dart could be compensated for by
changing the diameter, length, etc. I don't know why anyone would want to,
though, since the training value is still there with the dissimilar rounds
as long as the ballistic computer is correcting for the differences, meaning
no perceived difference to the gunner.

Brooks


--
Harry Andreas
Engineering raconteur