Here are pictures of the full bore Lee Key Slug
I had a guy cast. He took Lee Key mold and machined
it out to cast a .729" full bore slug. In picture
is a regular soft lead Foster style to compare with.
Slugs are hard alloy and can be speeded up ok.
In 2nd picture is two MRC 2 5/8" brass cases with
slugs in them. These slugs with those brass cases are
being tested first in rifled barrels in a guys 1887 WIN.
The slugs have real good shoulder to
roll crimp against when used in plastic cases.
These first ones are 500 gr. We are going to
work on another die to get the weight about 600gr,
that the brass case guys want to use.
Lee molds are not real high price so it isn't
a bad deal to get them and change them.Ed.

The first full bore Lee Key slugs were 490 gr,
that we had made. Good for 2300 in 3.5" plastic
and 27-2800 in 3.5" RMC brass cases in the
long barrel NEF.

For the 8ga Hubel Falling Block pictured
above; For now using 3.3" swaged kiln cases. We swage
them to fit the 8ga chamber in falling block.
The barrel is real thick so we can run 50-60,000 psi
if we want in that action. The heavy duty 8ga plastic will
take about 23000 psi. A MRC turned brass would do
35,000 psi. But the plastic does so great,for now I'm
staying with 70 cent 3.3" plastic, primed with 239 primers,
good for 4 shots or more.

And I have the REM wadcup, on left in picture, with
its own seal, that they use for the kiln slug, which works
for various other slugs and shot loads.

In the 8ga HFB - 3.3" plastic cases-
1020gr 2000 -- 900gr to 2200 ---- 770gr to 2400---
and triple ought buckshot load---
9 - 70 gr 000 buckshot, in wadcup. 630 gr total-- 2600.Ed

Remember these from above-Well 2nd picture is penetration tests with
them. Over 2000 for 320 gr weight in plastic cases..
3rd picture is an all aluminum version without brass center
from penetration tests. 198gr at about 2500 in plastic cases.
Now the locked on bases are not burnt and the reason I understand
is they use a thin card between seal and powder, up inside the
seal cup.This info and testing by US-S group in the EU.
The plastic cup seal out there might benefit from that, like
card disc inside the cup of the BPGS and similiar seals.Ed

In the early days; in my Greener's book he states that
gun with a rifled choke section of the barrel, called
12ga paradox shotgun/rifles, with slugs, heavier powder
charges than shot loads, could hold what amounted to
about 5 inch pattern at 100 yds.

And still had 1800 ft lbs energy at 100yds.
And that is with guns with lighter, weaker barrels
than we have today, so our work is a good extension
of what the early big bore guys did.

And then the 4bore for guys liking a big challenge, 3rd picture...Ed

Thanks to rattler on 24hr forum for the old time pictures,
above, and the guys really like them. Quite interesting.

Many have success with all kinds of high-power slug designs and
with extra power, have pushed the reliable range of 12ga slugs/bullets
from 75 yds to over a 150 yds. ...Here is picture from a 1926
Manton catalog showing, 1st picture, many brass case old time slug loads.
Notice the 20bore and 12 bore ones with pointed slugs, seems
as ideas to hotrod 20s and 12s are old hat, not as strong as 12ga FH ....
Both Pictures below from lancaster and CptCurl on Nitroexpress.

2nd picture are saboted slugs, called the SAGA, from Spain,
next to a Brenekke on the right..AS far as I can find only
sold so far as loaded rounds. They look great to reload with
if ever available..

3rd picture is from my Greener book, of double 8ga elephant guns.Ed

You can see 4bore, 8bores, etc, on you-tube..Ed

Here is picture of an early falling block for big bores
called the Field I think. Looks like some other
side levers, looks like lever works forward.

And speaking of falling blocks next picture is the
start or 'fixins' so to speak for the next step
up, for my 2bore. Same design as the 4 and 8
bores only wider.

I am now getting 2.25" OD barrel reamed
out to the two bore size.
And a square hole for breach block done
in that hunk of 4130 steel.

Other experimenting, a while back, when I made
my 585 Short HE from Gibbs cases, I also made a
620 Short HE from Nyati case, of the same design,
IE, head spacing on the mouth and extractor.
Using 600NE .620" diameter bullet and 2.7" long case.
Case could be shorter or longer like the 585 one.
Didn't do much with it as its sides were very straight
only .010" taper of both sides together. Whereas the
585 Short HE had .027" total taper both sides. And any
Nyati brass I got, went to make my 585HE cases..Ed

First is picture sectioned Explora case and slug, showing how
they kept weight down so that it could be stepped up in
speed in older doubles, with just short rifling section at muzzle,
that didn't have real heavy barrels. Second picture from Greener
book here, is of older 4 and 8 gauges.

Third picture shows steps of making 4bore case, one inch bore,
from 20mm. 2nd in picture is case with base turned and swaged
to size which leaves base smaller than rim, for rimmed case.
Then 3rd case has top expanded to take 1" diameter slug.
last shows the thickness and strength of finished case.

Testing factory 20ga Hastings sabot slug 3.5" hotrod loads, and
reloaded with 20ga SPW identical slugs, 390gr, goes about 2200
from 30" heavy barrel. Load was 75gr of 4759.
Factory is about 1900. For regular modern barrels you could
do with 65 gr and get about 2000.Ed

Some info about our slower powder reloads in plastic and
brass cases with shotgun primers for modern 12ga guns.
I now prefer the IMR 4759 over 4227 as we have had
some delayed firing problems when the loaded cases get
real cold with 4227..And with slower powder loads use
magnum primers.

A side note,in same vein, you know I now use FED239
mag primers in my 8ga and 4ga, but we find they they really
solve the real cold gun, ignition problems, in muzzle loaders
using black powder substitutes, with shotgun primer
inline guns. We tested 50cal and a primer sold especially
for ML when fired,no powder, only saw a tip of the flame
out the barrel, a FED209 mag about 4" flame, buta Fed 239
Mag primer about a foot of flame.

Some more info from the old days, here is picture of
a variety of slugs being promoted and used a century ago.
And 2nd picture Paradox cases old and new.Bottom one is a
modern version sold by H&H for slug hunters.Ed

We are always looking for way to shoot 8 and 10s
using easy to get components,cheap, without buying
loaded rounds for big bucks, if available at all.

In 8ga falling block, plastic got 930gr hollowbase
slug to 2300, It is a slug for 10 ga that we expanded
base a little to fit tight in 8ga wadcup. On the left in
picture. At 30 yds 3" group. Just with open sight,
About like the 10ga sight bead. There is enough hollow in
the base it flies pretty good from 8ga smooth barrel.

Along same line, in my 10ga 32" smooth bull barrel with a
750 gr .69cal hollowbase Dixie MZ slug in VP100
10ga wadcup about same speed and same accuracy.
Nice to just get a box of slugs that is in stock,
and a 2cent cent wadcup and Fed 3.5" 10ga plastic cases
and be shooting cheap.And the cases roll crimp nice
down to these slugs.

And also the hotrod 20 ga 3.5" Hastings factory loads in
a smooth barrel moderate weight 20ga shoots about
same accuracy even though they say for rifled, but that
SPW slug/wad combo has enough plastic and seal on the back
and to shoot like aBrenekke. The new 28ga Brenekkes
out of 28ga NEF modified choke barrel shoots same at 30yds.
Scoped guns and good eyes would shrink groups.Ed