On Mon, Jun 29, 2015 at 1:39 AM, Richard Aiken <xxxxxx@gmail.com> wrote:

> I'm frankly not sure how a sabot dropping away duplicates the effects of
> squeezing the caliber of the fired round down by ~30%.

I'm reasonably certain it doesn't.   The point of the sabot was to be
able to fire a small-bore projectile from a large-bore cannon, getting
higher velocity from the same powder charge, and better flight
characteristics due to the lower diameter and cross section.

The first you still get.  The second is not relevant in near vacuum.

>the
> sabot falls away just outside the muzzle.

Wind drag strips it off.  In space, you could just glue it on.  If you
can build gyros and sensors sturdy enough to withstand the launch, you
could use the space in the sabot for guidance.

>
> The squeezed/tapered bore effect would seem to be potentially much the more
> efficient of the two methods, since you've got the full length of the barrel
> to use for the purpose of increasing the effective gas pressure. However,
> APDS won out in practical RL use because it allowed you to use existing
> cannon (and existing much simpler cannon-boring technology) without
> modification.

Not to mention you can use a rifled bore to fire everything else in
the inventory, and a cone bore has to be a huge PITA to bore.

--

"Any sufficiently advanced parody is indistinguishable from a genuine
kook." -Alan Morgan