RE: 12GA From Hell
 

One of our testers, Bret in MN, got the BPI Sabot with
500gr Hornady .500 slug up to the good speed listed
on BPI"s loading sheet, using shotgun powders. I could
get them there with my loads using much larger amounts
of rifle powders. He tested 3.5" Federal plastic cases in
his Savage 210 with 3.5" chamber and the 28" heavy barrel
he put on. With 50gr of Longshot(max load for all modern
guns) he got 2550 fps, with 500gr in sabot. He use two
BPGS gas seals fitted together over the powder, then
a FS12 Flexseal wad, then a 1/4" cork wad, then the sabot.
Then a good strong roll crimp with drill/drillpress crimper.
This load is at mag shotgun pressures by case expansion
measurements and BPI's 46gr load tested at 12,500 psi.
He also did one with one BPGS and two Flexseals and had
200 fps less.He had tried other combinations seals/wads
and with same amount of powder and got lower yet.
He also went up with the powder, with seal/wads that worked
the best and got about 3000 fps, but the plastic cases
stuck and wouldn't eject easy. I will be testing same
seal and wad column in a few days, in my NEF with long
barrel to compare results.I thank Bret, he is a real
good experimenter and idea man. Everybody is trying
like crazy to get that 500gr saboted slug up to big
game gun velocities with shotgun powder and thanks to
BPI"s supply of the right components it has happened.Ed

RE: 12GA From Hell
 

Rob on AR is building a 12GA FH double on a Zabala Double
10 gauge frame. It has the Greener crossbolt. He cut off
barrels to make a 4" long monoblock double to screw a
pair of heavy 12ga rifled Pacnor barrels into. He reamed out
monoblock section and threaded it. His barrels are
1.116" at the breach, .97" at muzzle and 22" total length.
Barrels threaded into monoblock with a 15/16" x 32 thread.
In the pics it is partly done and he will put in the ribs
and integral sight rib and regulate for accuracy.
It will be about 14.5 lbs when done he says.Ed

RE: 12GA From Hell
 

Some more BPI seal and sabot testing.
First of all both Bret and I have heavy tight fit barrels
and his barrel on the Savage is faster twist so it took
him 50 gr of Longshot to get what BPI got with
looser barrels and slow twist at 46 gr of Longshot.
For non heavy barreled guns only go to 46 gr.
I did a bunch of tests in my NEF long barrel with long
chamber. My store didn't have any 500gr .500" XTP slugs
so I used some 420gr .512" dia lead Great plains in the
BPI sabot. Using 2 BPGS powder seals, a BPI Flexseal, a
cork wad in 3.5" new Federal cases, roll crimped, I got
2800 fps with 420gr slug. I tried 4 other powder seals,
2 cards, a Remington, a Win, and a odd one, all with the
Flexseal and lost velocity. I fixed up my crimper so it would
roll the plastic down and over inside edge of sabot, as before
it would turn plastiC in too sharp and get some of the crimp
outside the sabot top. If sabot was too low so that the plastic
crimp went clear down to the slug I got high pressure signs.
I also did same loads in used 3.5" REM cases ok.
Now, I thought I should have more velocity, so I swaged the
.512" 420GR slug down to .500" like they say the sabot is for,
AND I GOT OVER A 120 FPS MORE. Everytime. I also used
Alliant Steel powder and got all the same results, using
60gr. It is easier on cases. I also substituted the doubled up
BPGS powder seals and the Flexseal with 520gr Lyman in
place of the seal and cushion on the WW12 wadcup the Lyman
fits in, with some RL-17 loads, of 150gr, and got over 200fps more
that the original WW12 wadcup gave with the Lyman.

Velocity secret is to have the perfect sealing setup with
slug/sabot combo that is NOT too tight. Only tight enough
to get accuracy. The cork seems to protect the sabot
base ok on the shotgun powder loads, and not needed
on the RL-17 loads, which is a easier accelerating powder
and without cork helps make room for the RE-17. I think I
will get increases in the brass RMC cases, with RE-17, with
the BPGS doubled and a Flexseal in place of cards and wads.
We will know soon.Ed [/align]

RE: 12GA From Hell
 

Here is picture of the breach of 8ga FH NEF with
case in it, to show that the gun is strong enough
for 8ga. I was a 10ga NEF. Has 29" effective barrel
length, and the internal expansion step at muzzle
for the ports that stops muzzle climb and reduces
recoil. Which along with thick pad and thumbhole
stock makes for easy shooting.Ed

RE: 12GA From Hell
 

Here is picture of a 12ga size drawn brass case that was
made back in the 80s. Case is for the CAWS weapon system.
Case is belted, and it and the gun operated at 25,000 psi.
Its bore size is between 12 and 10 ga size, but the od of
the drawn case would let it start in 12ga chambers, so
they added belt so it couldn't go all the way in
to regular shotguns. Notice the thick sides and corner
near the base.Heavy enough for 25,000 psi. They loaded
it with big buckshot and test other projectiles also.
They had a plastic card over shot and filler and rolled
over brass mouth for crimp. Ed

RE: 12GA From Hell
 

Here is picture of a NEF breach barrel section that I threaded
monoblock style for a .585" cal barrel, to make a NEF 585HE.
It goes on a SB2 10-12ga alloy, super strong frame. Its
OD is 1.210" and the barrel that screws into it will be tapered
to match contour and it will be 1.00" at muzzle, at 32" long.
I know these are strong enough as my 8GA FH testing shows..
Later will do couple more with heavy barrels for 28GA FH, etc,
as all the break action 28 gauges I've looked at have too
thin of muzzles for our slower, powder loads.I'll have 3 of these
that fit one SB2 frame I have here.This makes switch barrels
big power fun.Ed.

RE: 12GA From Hell
 

I fired mono-blocked NEF this week with a 585HE 32"
barrel and the gun is weighted to 15 lbs. Thick pad.
I have cone breech as this case is belted with thick base.
I'll have a pic of gun later. Gun is still tight after testing.
I can take out cases with my fingers as they don't stick.
First 650gr, with no extractor. The HBMG, WC-860,AA8700,
Retumbo, Magpro, RE25, W-780 loads come out of the chamber,
with my fingers.If I tip gun up they fall out.
Top speed with RE25 and W-780 is over 2400. Now I knew what
to load them at because I have tested this case in 3 other guns.
I have all the different powders and bullets tested.
This is example of a case extracting easy,
due to proper side taper that my 585 has....Ed

RE: 12GA From Hell
 

keep the posts coming this is very interesting!
-Jake

RE: 12GA From Hell
 

Here is a picture of the Zabala that was a 10ga double,
that Rob has monoblocked in heavy rifled barrels, showing
the quarter sight rib he has made, fitted to the gun.
He has it chambered for 12GA FH long case.
Really beautiful work and gun.Ed

RE: 12GA From Hell
 

I found odd steel block with a square cornered
1.0" by 1.5" hole through it. It solves a big
machining problem for me in doing a 4bore.
And I happen to have some 1" by 1.5" steel.
The rest of machining I can do, and I have
the levers, hammer, trigger, etc. But the parts
and layout are not going to copy the Wickcliff.
To many problems with all the parts riding on the
breachblock and the crowded stubby extractor.
Will be my own design with hammer and
trigger behind breachblock. An extractor similiar
to Ruger and its shape a cross between WIN 1885
and a Farquarson.In pic you can see drawn outline
on the block of the shape it will have.ED