[SHR970]

I don't know what barrel length they used, I would assume 22" or longer.

SAMMI spec is 26" full choke.

Winchester 3" .410 slug, 1/4oz slug, 1800fps

A touch less than achieveable by a 30 Carb. with the same weight partially due to wad column weight.

I've got a box of Winchester 3" 000 buck (5 pellets). No mention of velocity. 1200fps and change is kind of standard speed for shot shells.

They get around 1100 fps from a shotgun.......at least from my Rossi.28" barrel.

So, I do have to wonder about the (recent) popularity of the .410 as a defensive round in the Judge & Governor revolvers..

And those same buck loads according to sources I have read hit around 780 fps. from the pistols.

2,400fps sound awfully fast to me.

When looking at slugs I can see this happening. The Remchester slugs use card wads in their column including the over powder wad. If you change that out for a gas sealing wad like the Gualandi Mini-Bior you can easily gain 100 fps right there. The two reasons are less gas blow by at the wad and also a much lighter wad column. A 110 gr. slug with a plastic wad (think Brenneke) weighs around 116 gr. Each of the three card wads from an older 2 1/2" Win. slug weighs 4.2 gr. for 12.6 gr. + 98 gr. for the slug. The 3" 110 gr. slug gets 3 longer hard card wads for even more weight (closer to 130 gr. total). With a 93 gr. slug + 6 gr. for wad and we are looking at 99 - 100 gr. Add in more powder to the allowable pressure and you can get into that neighborhood (think 30 carbine with 85 gr. bullet). The newer Winchester slugs are using a plastic filler column to eliminate one of the card was but make up for it with a much thicker cardboard over powder wad that was not included in the earlier weight figures.

I will be interested to see the actual load data but I suspect one other variable that I am withholding due to guess work.