If I found a Tonolini 8ga now I'd just use it as 8ga,
by shaving the base of the new kiln cases, like I
do for the 8ga I made from the newer heavy barreled
NEF 10ga. I get 7-10,000 ft lbs with it.

For monoblocking now, figuring in all the planning and
work, doing it on a Zabala double with crossbolt,
seems the way to go to make the best gun,
like Rob is doing.

RIP- My new experiments with seals shows the BPI BPGS
seals get more velocity as they stop leakage. Like 2 of
them gets 200 fps extra on 500gr BPI sabot loads, compared
to other seals we are working with. Maybe check them out
sometime with the heavy slugs.Might not get that much
extra on heavy solid slugs, but maybe a hundred.
I'm going to use them on all my loads now instead of
cards in brass and plastic.Ed

RIP- Your pretty much dead on with Quickload at this point. It would be interesting to see what a booster charge does with 220gr of Rl-25. I may try that myself. I'm prgogramming today for the quarter rib and about to cut the top and bottom elegantly curved ribs out of some steel I found. Looking good!-Rob

Ed,
Thanks for another tip, on a gas seal (BPI BPGS) replacement for the nitro cards.
It is about time to make another order from BPI.
I need more of those clear plastic over shot disks too, now my first choice for "X15" Blue Dot starter.

Rob,
15 grains of Blue Dot X 220 grains of RL-25 = 220.0 grains of "X15RL-25" ... Try that load in Betsey Borchardt first and chronograph it to see if turns RL-25 into RL-19.

Kids, don't try this at home!!!

I'll try that in QuickLOAD with current "modeling," maybe even try for bullet base shape approximation to boot, for a closer "virtual reality."

I am ordering an off-the-shelf .730" back bore reamer from Brownells.
Will make my own lead slug sizer.
Lee .730" sizer in Limbo still.
PT&G lost my previous order. A first for them!
I could try CH4D ... for a .730" sizer ... but I may have my own made shortly, before Lee ever gets to work on 6-month-old order.

Crazy out there.
The Obamanation is hoarding all things shooting related?

Hopefully we don't all end up in some kind of "Matrix World" doing nothing but virtual handloading on QuickLOAD.

It is the aluminium darwins that tame this beast.
Rob... What about making a minimal bearing surface bore rider traditional FN truncated cone design version?

Boomstick - No Problemo, but Why the current ones work fine. Too busy prgraming the quarter rib for the 12GaFH double to get distracted right now.-Rob

Aw shucks! Rob, you better make sure the major medical and disability insurance are paid up, just in case your double rifle doubles!

I was carelessly quoting only the bullet recoil effects above, still getting used to QuickLOAD. That would be the least recoil possible with a 100% efficient muzzle brake. I will quote the QuickLOAD-calculated total recoil for two of your loads and one of mine below.

I added the boattail base effect and I am done with adjustments to QuickLOAD ... until I get into some calculus of the bore area with NEF "ultragon rifling." Your Pac-Nor rifling (on Betsey Borchardt and the double rifle from hell) is different anyway. The default bore cross section area is undoubtedly within +/- 10 fps anyway. Good enough.

12GaFH No.1: 1085 grain Brass Darwin
RL-25
220.0 grains
22" barrel
1780 fps
24,083 psi
7636 ft.-lbs.
10.5# gun recoil: 248.61 ft.-lbs. @ 39.02 fps

12GaFH No.1: 1085 grain Brass Darwin
RL-19
220.0 grains
22" barrel
2006 fps
33,651 psi
9699 ft.-lbs.
10.5# gun recoil: 292.93 ft.-lbs. @ 42.35 fps

12GaFH No.2(09): 1382 grain Hard Lead Darwin
X15H50BMG
"215.0 grains"
(215.0 grains H50BMG + 15 grains Blue Dot + CCI-209 = 218.6 grains of Retumbo + CCI-35)
22" barrel
1565 fps
20,894 psi
7520 ft.-lbs.
11.5# gun recoil: 264.13 ft.-lbs. @ 38.43 fps
(Approximation which does not account for 11.4 grains of additional powder burned nor the weight of the plastic disk ejected:
recoil will be a gnat fart larger.
However since my VAIS Brake is so efficient, I may be dealing only with the bullet recoil:
161.41 ft.-lbs. @ 30.04 fps.)

I called Dave Casey at RMC.
3.85" 12Ga brass is still in the works, but he is also swamped by the "Obamanational Gun Culture Hoarding Frenzy."
Maybe this will be the way out of this recession, "unintended good consequences" of bad policy.
I am in the queue there too.

That brass could be called the "12 Gauge 3.85-Inch Everlasting" if for no reason other than the thickness of the brass.
Firing 12GaFH NoHbozo brass in the chamber suitable for the RMC brass will overwork the brass in resizing,
and likely split the case on the second shot, if not the first.

The RMC brass will be "everlasting" indeed at 20K to 25K psi.

Who cares if Nohbozo brass in a Nohbozo chamber is good for twice that pressure?
A man has got to know his limitations.

I think your going to find that the RMC brass wont be everlasting. Its so thick that if it moves at all it will crack after just a few reloadings. remember the true 12GaFH is a 55kpsi cartridge, capable of phenomenal horsepower. These are really entry level experiences.-Rob

As long as our long case is annealed to start
when its expanded first time , it will go many
times in my NEF which is out to regular 12ga
mouth dimensions. It is tough stuff.
One I fired about 10 times in NEF. No cracks
and I just annealed again, and still good.
And the RMC when fired in the same chamber where it is
snug fit will go many times also. One here over 20
times and will do 40 at least I think.Ed

Good to hear, Ed.
Rob, I will see what powder is needed to get the 1085-grainer up to 55Kpsi, with a case full, per QuickLOAD. Hospital level recoil?

Those RMC cases fired at 20K to 25K do not seem to move at all. They still have some crimp at the case mouth after firing,
still cause some friction on a Nohbozo slug inserted by hand after firing.

The bases have zero expansion in the 20K to 25K psi range in my gun.

I vow to endeavor to persevere at proving them to be "Everlasting."
Ed has already got a headstart on me.

If Rob can get his double rifle to double-fire with 55Kpsi loads, it is time to call the chopper in,
and head for the nearest trauma center:

12GaFH No.1, 22" barrels, 1085-grain Brass Darwin, 10.5# gun:
(If the double rifle weighs 14 pounds instead of 10.5 pounds,
then multiply the stated recoil-energy and recoil-velocity by a factor of 10.5/14 = 0.75, i.e., 3/4 as much)

RL-17 233.0 gr:(101.7% fill)
2371 fps
54,247 psi
13,539 ft.-lbs.
Recoil: 383.77 ft.-lbs. @ 48.4 fps

RL-15 220.0gr:(100.7% fill)
2352 fps
54,813 psi
13,330 ft.-lbs.
Recoil: 367.75 ft.-lbs. @ 47.45 fps

RL-17 is Velocity Champ ... and can be set off reliably by a CCI-209 primer?

233.0 grains of RL-17 in a 22" barrel with Rob's 1085gr Brass Darwin is the champ for velocity below 55Kpsi,
and is 98.6% "Propellant Burnt" with 30.5% "Ballistic Efficiency."

But H4895 is the efficiency champ in same barrel, brass and projectile:

H4895 218.0 grains: (103.2% fill):
2324 fps
54,812 psi
13,007 ft.-lbs.
Recoil: 359.43 ft.-lbs. @ 46.91 fps
99.9% Propellant Burnt
32.6% Ballistic Efficiency

Some of those H50BMG loads are about 50% burnt in a 22" barrel at the low pressures.

Now, if RL-17 can be set off by a CCI-209,
here are a couple of heavy-slug loads at pressures to make the RMC 12Ga 3.85" brass "everlasting":

12GaFH No. 2(09) Everlasting
1382-gr Hard Lead Darwin
24" barrel, 11.5# gun:

RL-17 160.0 gr.: (69.2% fill)
1578 fps
20,931 psi
7637 ft.-lbs.
Recoil: 225.90 ft-lbs @ 35.54 fps
89.7% Propellant Burnt
25.0% Ballistic Efficiency

RL-17 166.0 gr.: (71.8% fill)
1637 fps
23,024 psi
8224 ft.-lbs.
91.7% Propellant Burnt
26.0% Ballistic Efficiency

Nitro card, fiber wad, and BPI-BPGS gas seal could be used to fill the case, CCI-209 primer, and no starter powder.
I gotta try that.

Maybe double Brown Bess balls?

A stack of three 0ne-ounce Foster slugs?

W. W. Greener designed a .321 Greener Multiball, using a "triplex load," a stack of 3 .332-cal bullets
in a weird double-shouldered, flanged brass case about 3.25" long, circa 1921:
"The idea of the plural bullet was to deliver as much shocking power as the .600 nitro express."


Been looking

Not exactly on topic, but I recently bought a Taurus " Judge" revolver and have been making some turned brass cases for it to launch some .452 Quadracones. It definately can lay down the law!
Rl-17 looks good to me. Gotta try some.-Rob

Rob,
With your Quadracones, you have done W. W. Greener "one better."



Fred A. Datig's CARTRIDGES FOR COLLECTORS VOL. III, pg.105.

RIP- Thats interesting. I thought about hollow bases and stacking the quadracones, but was worried about their getting fused or stuck together on firing. Thus I made those simple plastic spacers. Quadracones in the 12GaFH are truly amazing and I seriously doubt that a Honda fulla gangststas would survive a single shot. Each cone has a hole drilled in the base off center to cause dispersion.
The "judge" in 45/.410 can use 3 inch magnum .410's that hold 3 OOB rounds. My brass cases actually also have a stupid looking step needed to get past the .45 colt shoulder! I think 4 quadracones and 5 shots will be a most excellent home defense weapon. Whose purpose is to provide time to get to a 12GaFh loaded with Quadracones of course!.

Rob,
That same book by Datig has a .308 Winchester Nato loading with two bullets.

Looks like a normal .308 outwardly except for three grooves on the case body to mark it as "different."

The bottom bullet has a slanted base instead of square, maybe 30 degrees off square.
Its nose rests against the base of the top bullet which is crimped in place like a normal bullet.

The bottom bullet is buried in the powder.
The top bullet leaves the case with relatively normal velocity and accuracy.

The bottom bullet has "indeterminate accuracy."
It also is considerably slower.
Good "spread" of the "two-shot group" results from both the lower velocity and the eccentric bullet base.

Apparrently the expanding gas and burning powder gets between the bullets
and the leading bullet gets better acceleration than the trailing one.

I think you might be able to go to a Hexacone load by having the points of the cones nestle in a conical base recess.
You can still have the eccentric holes drilled in the bases for spread too.

If the base holes go all the way through, the gas "blow" will also help separate the cones as they go down the bore.

You also might try varying the hole size to get a harmonious whistle down range.

Ed,
I found some RL-17.
Sure hope the 209 primer will light it off.

As long as good hard crimp in plastic and
tight fighting crimps on brass cases, it'll work.
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

Ed,
I have one of those 10 Gauge NEF-ers, and it is all your fault! But I am not ready for 8 Gauge, having too much fun with 12 Gauge for now.

All your tips have worked great so far.
I have no problem with getting a crimp, and the resistance of 1382-grain slug inertia will make it even more reliable.

BTW, your photographic skills or your camera improved.

Ed- How about a pic of the chamber end of your 8 bore. What is the thickness of your chamber wall at the base of the shell?
I've made great progress on the DR. I have made upper and lower rib material and written a prgm for the quarter rib that if all works out will be machined internally to cover the residual rib from the zabala monoblock and once welded and soldered in place will be invisible. If the peening between the monoblock and barrels works as planned, the joints too will be virtually invisible and only a very very carefull inspection by a real expert will reveal the secrets of its manufacture. I am aiming for a very professional looking DR. I may take it on a road trip to the GRAND VISIER of Boron for professional regulation instruction though.-Rob

The chamber walls are .140" thick.
I run operating loads with super strong
industrial cases at 20k psi. That still
gets 9-10,000 ft lbs in a plastic case.
Those cases can be fired 4-5 times with
no basecup expansion, so I think they hold
so much that there is less strain on the
breach, than when the gun was a 10ga.

Everyone across the net loves that double.
It's the best thing anyone has done so
far in 12GA FH.Ed

Ed- Thanks for the info. The chamber walls on the 12GaFh in the Zabala are over .300 and I was a little worried at first. I've done everything so far by CNC so my gun can be totally duplicated for anyone else who can source a 10ga Zabala. I plan to chamber the gun in a week and mount the quarter rib and forearm locking mechanism. Then its regulation time. It should go boom in the next few weeks. The biggest issue is what load to regulate against. I'm leaning on a load that would be surviveable,i.e. about 500ft-lbs total should the thing ever double. My guess is that higher power loads will still regulate reasonably well.-Rob

Rob That's some beautiful work you're doing. I've always wanted to machine a double from a block of 4140 (even bought the material) but never got around to it. I never thought of using an existing action and altering it. Please keep the pictures comming I really want to see this all come together.

Fritz454- Thanks coming from a professional machinist thats high praise indeed. I wrote a nice program in Bobcad to make a monoblock for a zabala and I plan to make one once I get this one finished. Having a working model is a big step up and the only hard part will be fitting the action lugs. I took the easy route for my first try. This thread is now over 70K views!- Rob

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 roll
over brass mouth for crimp. Ed

All that space and no Quadracones?-Rob

I have a question. If I bought an NEF slug gun and reamed it out to 3.5", how much damage could I do?

Where would I buy the stouter cases, what pressure could I load to, what velocities and energy levels could I get? Would I need to ream a longer throat or does the factory gun already have a real long one, etc.

What about dies, would I need a special press? My 45-120 isn't "enough".

When you ream it with a 3.5" reamer, the reamer extends the
throat also all in one simple operation.
You can get 3.5" cases from Rob as he will make
them any length you want. Or from Rocky Mtn Cartridge.

AS for damage if you weight the gun, put on thick pad, put
ports on barrel end, you won't hurt yourself with heavy loads.
As for power you can get 1080gr slug to 1800 fps,
and lighter ones faster.Ed

Tyler- Why would you want a 3.5 chamber when a 3.85 chamber puts you into the big leagues? Figure it this way. Including the price of the NEF itself for about $1000 you can have a fully functioning 12GafH( including the muzzel break), for 8000ft-lbs of Muzzel energy, full reloading set and ammo. This thing drives a 1085gr .729 slug to 1800fps. I dont think You can get anywhere near that kind of power in a rifle at anywhere near that cost with anything else. You can still shoot std 23/4 birdshot,3" slugs, sabots etc with the same gun. Its about the most bang for the buck that exists.-Rob

Yes, the most bang for the buck possible.
And you should be able to do homemade hardcast lead slugs of 1382 grains at about 1600 fps and 20,000 psi.
This will expand the RMC cases zero.
The soon available 3.85" RMC brass will be "Everlasting."
This will dwarf the penetration of Randy Garretts's 45-70 Hammerheads, and it will dwarf the TKO of the 700 H&H Nitro Express.

I cut a 5" segment off of one of the 30" barrels I got from Ed.
I left it with the smith today, along with the PT&G "12Ga From Hell Everlasting 3.85-Inch" reamer and a Clymer .730" backbore reamer obtained from Brownells (2-day delivery time).

I asked my smith to thread one end of the chunk for 1.25"x12TPI, to fit a Lee Classic Cast press,
then insert the shotgun reamer to 2.5" depth,
then remove the rifling of the remaining 2.5" with the .730" reamer,
then polish up the internals like he would do a custom forcing cone job.
I'll see how that works for sizing my lead slugs to .730" or thereabouts, .731" would be O.K.
Pure lead Darwins weigh about 1438 grains and cast about .730" diameter from the Brooks mould.
30:1 is about 1400 grains and about .732".
Rippalloy No.2 is 1382 grains and about .735"-.736" diameter, BHN 22, water-dropped,
hard as Linotype and less brittle, I hope.
Those diameters are approximate, off the top of my head, but that is the trend of lighter and bigger as hardness increases.

I've been waiting over 6 months for Lee to make a slug sizer. Maybe they will eventually gitterdun.
It ought to be a standard item, not a custom order.
Maybe it will become so now that Rob has breathed life into the 12Ga From Hell, and the 12Ga From Hell Everlasting.

I don't have the money for all the 12 GAFH supplies, I was hoping maybe 3.5" stuff would still give me plenty of power and be a lot cheaper and possibly be able to find some dies that weren't too much that I couldn't afford.

You can get started putting a 3.5" chamber in NEF Ultra 12ga.
Use 3.5" plastic, with a steel roll crimping tool for drill
press. Litle case holding vise. Get over 6000 ft lbs.
Buy new 3.5" cases already primed for 18-30 cents each.
Get various slugs,sabots,wads, seals, some RL-17 and 4227 powders,
and your shooting. Then you work up to brass case.Ed

Tyler-Just send the barrel over and I'll ream it to 3.85 for you then go shoot anything you want in it. Depending on whose 3.5 reamer you use(ie what its dimensions are), you may wind up with a chamber ring that could compromise extraction. My 3.85 reamer leaves a very faint ring that causes no problems but was never designed to completely clean up a NEF chamber. You'd need to chamber cast your NEF and compare those dimensions to your 3.5 inch reamers to be sure you will be able to live with the results. The recoil without a muzzel brake will self limit you to very safe levels.
RIP- I could knockout a .730 bullet sizer for you if you want. looks like i will be doing one for another guy soon. -Rob

Rob,

I just picked up a brand new Savage 210F for less than $500. Could I really have a Godzilla Killa(aka 12gaFH) for less than $1K invested? WOW!! I need to start saving for parts!! I'd love to have it ready for the Shoot and Hoot next year south of Houston if possible with out breaking my bank. Other than a new barrel, a muzzle break and a couple mercury tubes, what else do I need and how much will it set me back? I am a fulltime student working 32hrs a week, so I gotta be careful with my budget.

Andy B

drewhenrytnt- Ed knows more about Savage actions than I do but I'd say for $1100 your pretty close. Figure $300 for a barrel, $300 for gunsmithing and the rest for reloading tools, brass and bullets. The savage will handle 40KPsi loads so its getting right up there in the 10,000 ft-lb range. Thats rarified territory and you will need a muzzel break or you'll need your student insurance policy.-Rob

I cant belive this! I have just found out that any firearm and ammo (including components) that are .50"Ø or bigger are classified as items of "Warfare". To import such items needs to be given approval by written authorisation of the Minister for Justice and Customs, written permission from the Commonwealth Attorney-General’s Department and the Minister for Home Affairs. How do they think I am, some radical bloody rag head FFS!!!

So where does this leave me, it leaves me making my own brass, my own projectiles and telling the bloody lot of em to go an frack themselves!!! Thank frack I'm getting a lathe. I'll have to do the same thing that RMC does, turn the casings out of brass stock. I tell ya, some day's I'm sorely tempted to go postal!!!

This all came about when I tried to import the full bore projectiles and some casings. The paper work, the hoops you need to jump through, its all to much. It will take over 4 months to get all the paper work done (thats if it doen't get "lost" in the system). So my 12GFH project has come to a grinding holt untill I can get the new workshop up and the machinery installed. They have right royaly pissed me off so now I'm digging my heals in! Come hell or high water I'll do it all myself.

quote:

Originally posted by Robgunbuilder:

RIP- I could knockout a .730 bullet sizer for you if you want. looks like i will be doing one for another guy soon. -Rob

Rob,
Very kind of you. I'll take it!

Along with the Lee (on order for over 6 months),
and the homemade design the smith has parts for now,
yours will be the third on order.

If some precision machinist with a lathe does not eventually come to my rescue, I will be hand reaming a segment of barrel,
and hammering slugs through it with a mallet!

Condolences to Gibs in Oz.
It could get worse here.
Hopefully we all don't come to mixing our own black powder and scrounging for flints.

I picked up my NEF a few weeks ago, and just got over 50 rounds of .50 BMG brass for *cheap*, so I'm all stoked! Need to get the barrel chambered (or make my own reamer if I can find the time) and load up some slugs.

A question here - I've done a very small amount of reading on primer tubes, and they seem to be a really good idea for such large loads. Has anyone given any consideration to this? Would be interested to hear thoughts on whether or not it would provide any benefit for this round.

Here's my NEF next to my limited-edition 10/22. Love those matching stocks!

hcpookie,
If you are going to use 50BMG brass with CCI-35 primer, why would you want to mess with a primer tube inside the case?

Are those see-through rings on that 10-22?

The CCI-35 primer is all you need to ignite all the powder a .50BMG case can hold. Dont think primer tubes add anything and may not even work. You really really dont want to have a hang fire with these cases! I can ream your barrel and modify your cases for 12GaFh. PM me for details.-Rob