Here is picture of 585HE with 24ga FH ...585 the longer one.
Both use same bullets/slugs, same caliber rifled barrels.
Different easy usages, 24ga FH is an easy setup in break
actions and 585HE in bolt actions and falling blocks.
Picture of non-discarding 585/24ga sabot cup I found that holds
458 bullets and slugs tight. It had hammerhead type slug in it that
someone pulled out, and they wouldn't stay in tight after pulled.
Supposed to be for 20ga, But this sabot was a real loose fit
in 20ga, though made for 20ga, so I shrunk diameter of bottom rib,
fits perfect, super tight, in 24ga and 585HE brass cases. A press
in tight fit gives good resistance for good ignition. real tight fit.
Here is a 24ga/585 discarding sabot that holds .452" 45cal pistol
bullets. Made by Hornady for 58cal Muzzle loaders..
With 250 gr bullet in 585HE, hopped up load will go about mach 4.
For ease of getting actions in stocks, I like composites.They are
strong. come colors, many can be painted with tough finish paints.
Usually need weight added for big bore use. But not too miuch..
An easy way to weight plastic stocks with hollow butts, use rubber
coated computer mouse balls, weight comes out perfect, without being
too heavy if using that much lead. And coating keeps them quiet, and
we hold them in, with piece dense foam under butt pad....Ed