As long as your 20ga barrel is a heavy rifled one with
diameter like the 600NE barrels.
Working more with 58cal lead slugs in 12ga sabot we want
to get built. We shot a few for checking penetration,
with 440gr slugs at 2200 plus fps. Shooting into popple.
In picture the 6x6 on the left penetrated by harder lead
alloy slug, with slug showing very little expansion on
exit from the 6x6, On the right, soft pure lead slug through
a 4x6 starting to show expansion on exit. These slugs can be
gotten or cast your own to about any hardess needed.
They can even be heat treated to be as hard as jacketed.
I have rounded up 9 different ones very easy, shown in
2nd picture and there are more. Ones in picture range
from 400gr to 530 gr. There are molds to make them
down to 350 gr and less.
Here is picture, on left of Accutip sabot we been taking out
of loaded rounds and testing 58cal lead slugs with,
and right a hard plastic sabot model, we are working on
to see how slugs fit and how it looks, and how
it compares to the Accutip and other sabots we have
here from WIN, REM, FED, Hornady.
In picture is a really neat, very strong, 10ga Beretta style
gun we got. Its barrel is heavier at the muzzle than most
all 10 gauges we've seen except the NEF with bull barrel.
Made by Pedretti, has top lever to open, instead bottom
lever like Beretta or the Investarm 20ga we showed above.
Going to make into switch barrel for 10ga and monoblock one
in 585HE later. Have 2 barrels for it. Has nice big pad we put
on it and it is weighted to 12 lbs in 10ga..
Now for some internal ballistics comparisons.There is formula
for figuring appoximate Average Barrel Pressure,
You take Muzzle Energy times 12......and divide it by
the BORE Area in sq in, times the length of the barrel in inches.
Examples- you have a 458 WIN, my 585HE and 12ga 3.5"--
all at 5000 Ft Lbs of energy which for 458 be standard load.
The 585HE in this mode would be burning close to charcoal.
The 12ga 3.5 would be 440gr slug in sabot at 2200 plus.
The 458 Ave Barrel Pressure is about 16,000 psi.
The 585HE Ave Barrel Pressure is about 8,000 psi.
The 3.5 12ga Ave Barrel Pressure about 5,200 psi.
The purpose of this-- To show the possibilites of big bores.
Ok you can't go much higher with 458WIN, about 80gr of powder
But 585HE you can get way over 10,000 ft lbs,with 180gr powder
it holds running at 458WIN Ave Barrel pressure.
AND 12ga and 3.5" brass case in Savage 210, slow powder loads,
heavy barrel, you can get over 10,000 ft lb. with 180gr powder
at much less than 458Win Ave Barrel Pressure.
Possibilities are really great fun. Ed