I have two actions here now to try some base development work on a 12 guage heavy. I do not believe either of the actions strong enough to take full power 12 gauge from hell, thus the next rung down, the 12 gauge heavy. I am trying to achieve a 900-1000gr slug at about 1800-1900fps and will be trying to keep loads to the high 20's to low 30's in pressure. The actions available dictate this as well as this being all the power I really want to achieve at this time. I still want the rifle to be portable, so when the weight has to go over 15lbs to keep recoil down it is outside my window. Has Pac-Nor finished any of the barrels yet? Also I am not equipped to make brass so I would need to trade or buy some off someone with more machine tools than myself. I belive these lower pressure loads to be compatable with a large break open action with a greener crossbolt. I prefer not to work with the other action unless I need to.

Pyro,
The range you are shooting for is attainable, and from a number of ways. That's a cast bullet practice load for a 577 nitro, and bricked out max for a 577 BPE.

Wayne has cast bullets for you, www.customcastbullets.com and your heavy.....

If you have someone make you brass, you'll have an upper pressure limit on the turned brass... I forgot what that is, but I believe it's under 30.

have a ball,
jeffe

Pyro-Do you have barrels with those actions
and are they steel barrels.And if so how thick is
barrel at breach(chamber sidewalls).And diameter of muzzle.If they are heavy enough, you could
load 900 gr up to the speed the Paradox doubles
got, about 13-1400.You would only have to lengthen chamber, and could still use magnum shotshells.
In other thread Mickey1 had a H&H 10 double that was heavier to use as a monoblock, to screw barrels into.Lar also had one a little lighter.
Both had crossbolts.
I don't think Rob has Pacnor making them yet, as we all are figuring out easy types of actions to build them on.I am getting barrel
when he orders, I even have the green.I will
have Greener-martini here Monday that I am going to try.Am also looking to find a heavy 12ga to
test lower pressure loads like you want to do.
Of course with the 12GA FH cases built from BMG brass that will allow 5000 psi more compared to plastic or the old balloon head brass..Ed.

Well hold on to your hat Ed. I finally got my ATFE approval. I�m looking at doing a 20 % larger high wall for the 12 gage from hell. Your 700 HE should work well in it as a poor mans alternative to the McMillan.

After the news I've treated myself to a bit of Dom but will be back at it strong tomorrow. Patience is in fact a virtue.
John

IMHO the scaled up Hi-wal from Fritz 454l is definately the best way to go. I think you can also get there with a Mcmillan Bolt action, with a specially machined bolt, but it's iffy and a very expensive experiment. I'd stay away from any shotgun action or single shot for safety sake. there is an enormous amount of bolt thrust generated by this thing and if we are not carefull someone is going to get badly hurt.-Rob

The mechanics of the hi-wall design makes it a very strong action and although you don't have a mag full of rounds reloading is a matter of practice. Besides this thing is going to kick like a Kentucky mule and recovery time is not going to be all that fast anyway but if you can hit what you want it is not going to recover all that quick either.

I�ve also thought of scaling up a Ruger #1 but that has a few more sticking points so the hi-wall will be first. We�ll see on the #1. I�m open to suggestions but realize whatever it is it has to have to have some amount of broad appeal.
John

By the way I think I can do the Hi-wall for A LOT less than the McMillan even though I truely belive they make a first class action.

[ 09-19-2003, 07:20: Message edited by: fritz454 ]

John-That is Great news.Should make it 30% bigger.
And if you can save me some bucks for one for
my 700 HE, that will help.
Rob, in your plans for the scaled up High-wall
that you got, how big is barrel thread.
John and Rob- I think that barrel thread for these
BMG derived cases should be 1.3 inches, so that a 1.5 in barrel gives .1 in shoulder.Action
about 1.8 in wide.
The other matter of using break actions and
Greener-Martinis ,is the reason we should check them out,I will do a Greener and a regular heavy 12ga.Have loads all figured for working up to safe pressures, and a few 12GA FH cases made.
When I get a heavy 12, I will test it with 600NE
900 gr bullets in a sabot. And I know at a little above shotshell pressures that you can get it
to about 3/4 of 600NE velocities.In a beefed up Greener it will outdo a 600 NE using sabot.
And like you said in other thread in a high pressure action the 900 gr saboted would be
in overdrive.Ed.

Hey Fritz, I was in your town the day before yesterday picking up some Fedex at the airport. I would purely admire a chance to see this monster while I'm in this neck of the woods, if we can arrange it. - Dan

I have successfully modified a Greener 12/14 barreled action so that it will work with a .50 BMG primer and it can be modified ( with a boring bar) to accept a shortnened version of the 12 ga FH. The action length is simply not long enough to feed a full sized 12ga FH. Maybe a 3.5 inch COL would work though. The barrel walls are WAY WAY too thin for my way of thinking. I don't know how much additional pressure using a .50BMG case will allow, but I'd want to extensively proof test maybe even destructively test one with a recording strain guage before I touched one off anywhere near my head. While it would be a really interesting idea to simply scale up a Greener action block., there is a cut in the action that supports the rear of the block that I simply can't figure out how to make other than by investment casting or by sinker EDM( which will be unbelievably tricky). This cut is part of the locking mechanism of the loading/ firing pin block and it's dimensions are critical. I've pretty much abandoned the Greener except for a low pressure model as a result.
Fritz 454's high wall and /or a very modified mcMillan action remain my two best choices.
As to barrel threads, I think I'd suggest a 1.5 inch thread max dimension and 14 TPI threads. There is not alot of support area even in a high wall and this argues aginst using coarser threads.
Fritz454- I mailed you the Hi-wall plans yesterday.-Rob

[ 09-19-2003, 20:14: Message edited by: Robgunbuilder ]

Dan, You have a PM

Fritz,
What is the largest rim diameter you can fit in your enlarged highwall? I have 2 8ga shotguns (SxS & Single) and would like to have a steel barreled 8ga (mine are fine twist damascus) for 'heavy' loads . I have 20 brass cases & 150 Remington plastic cases with the extra brass band swaged down and they push 2-2.25oz of shot with blue dot. However, a steel barreled 4" chamber pushing 3-4oz of shot would be great, ESPECIALLY if it had a switch barrel 8ga rifled barrel as a companion. Oh to dream.

BMG

The actions are both 10 guage actions, thats why I was looking for the barrels. I was mostly interested in using the 50 bmg brass based 12ga from hell concept, but maby a bit shorter and at lower pressure. I have a 20 or so 12 guage paradox loads and some brass, but they are not fit to be fired in a modern 12ga barrel, they are 12 bore paradox and by my micrometer a bit bigger in slug diameter. I believer the 12 bore paradox guns were larger than the .72 size of modern 12ga. At any rate the brass I have will fit, but 12ga slugs will not fit the brass, too small. I am just playing with this idea as it makes a nice gun I can take to another country with me, there they only allow shotguns. With a 12 gauge heavy I have a "shotgun" by definition but also a gun capable of firing a heavy slug at medium velocity. It cannot be a bolt action, and I can only work with a sxs or single shot traditional shotgun action, I do not even theink I can use a falling block. My goal is a 12ga that can handle standard plastic hull loads and also take a heavy brass heavy slug medium velocity load. That is what attracted me to the 12 gauge from hell project.

Pyro- You have a good concept there.Regular 12 ga bores are .729, and I thought the same as the Paradox guns..They make modern shotgun slugs small with expanding bases and a wad behind to
expand on firing to fill smooth bore.Makes them work the best in shotguns smooth bore,We
investigated using a .729 bullet and rifled
12 ga heavy barrel.OR use a smooth barrel and a nose heavy .729 bullet and I am going to test
a saboted 600 NE 900 gr slug.I favor smooth barrel
as that works best with shot shells,I can get
600 NE bullets, and get a tight fit with sabot.
AND as long as it is break action don't shorten brass, as that gives the room to work with sabots,
and shot shells will still work great.Are your
brass cases the old balloon head style.If they
are that may not be strong enough. How long are they?And if you can get 900 gr saboted slug to
1600, that's 5100 ft lbs.And with these cases from
BMG brass that may be doable.Ed.

pyro and hubel:
Paradox projectiles are generally accepted to have been .735 diameter, although there has been quite a bit of variation in actual measurements. The reproduced Kynoch drawing of a paradox projectile on page 148 of Graeme Wright's second book actually specifies .7345-.7355. The Paradox mold manufactured by Jim Allison (Cast Bullet Engineering) is .735 nominal diameter, so most of us start with that size and go up or down a thou or two as required.
Hope this helps.

Marrakai-Thanks for info.We plan on staying with the .729 size as it should work with shotshells
better.Is the Paradox bullets you use solid or
hollowbase like our Foster slugs?Are Paradox guns rifled?That's the only problem I see with my idea of using 600 NE bullets in a sabot for smoothbore, as they may not stabilze.Can you use shotshells in Paradox, with good patterns.I wonder
if a Foster type slug about twice as long and heavy could be cast.They might be as stable as Fosters at same ranges.Ed.

Ed:
Paradox projectiles made to Fosbery's patent are nominally 750 grains weight, with a flat base. A variable hollow-point for thin-skinned game can be used to reduce the weight to near 700 grains. They have what looks like a lube groove, but it is really a 'waist' to lengthen the projectile and reduce bearing surface. They load in ordinary shotshells (paper and plastic) without any problems.





The typical paradox barrel has a .735 bore, with a 2-inch long full choke. Five thou deep rifling is cut into the choke. The projectile gets squeezed slightly, then takes the rifling. The chief advantage from my point of view is the recoil reduction, as the projectile is accelerated to full velocity in a smooth bore with a thou or two of margin, and after the recoil from acceleration has well and truly dissipated, it hits the rifling and gets it's spin. As a result, the guns could be made around 7 1/2 pounds weight, whereas a fully rifled 12-bore with similar ballistics needs to be around 11 to 13 pounds.

The marketing advantage at the time was that it would still make a reasonable pattern with shot, hence the hunter so-armed was ready for anything "from tiger to snipe"!



This is a principle worth further investigation for the 12gaFH, as I reckon recoil and rifle weight will be a serious limitation. There's a fair bit of detail on the paradox principle in Hollands' book "The Shooting Field".

Marrakai--That's interesting.
Real great pictures..What lead hardness
did they use back then and you use now.
We could get our heavy barrels smoothbore.And
then if we needed extra stabilization, add a
section with the choke and rifling.Easier
to build for barrel company,Save on barrel cost.
For stronger guns you could make them longer by the length of that back base and groove section,
or multiples therof.A 2 groove on would be about
1050 gr, a 3 groove 1350, and 4 groove 1650.Ed.

Marrakai
Thanks,,, this was fantastic, and, I had thought the old paradox guns were indead 12 bore.

Ed, rob, hell's bell, men, you could do exactly this with the FH guns, pick up some velocity...

John, you've got an email

jeffe

Ed:
I think the original Fosbery projectiles were pure lead, but if memory serves me correctly, Baker may have used hardened paradox slugs for buffalo etc in Ceylon. I'll check this. Hollands' 10 and 8 bore slugs had a steel insert!

We add a bit of tin to ours to make them cast well, but current thinking is that dead soft shoots best. These days, we patch the projectile with teflon plumber's tape to avoid leading the bore. The cartridge in the photo is trimmed to 2 1/2 inches: it was chucked in a collet and spun in the lathe, while being squeezed in the appropriate place with circlip pliers! We don't do this anymore, too much mucking about! Now we roll-crimp onto the front shoulder of the projectile using a specially built roll-crimper (relieved in the centre, to accomodate the projectile nose). Photos in Graeme Wright's book.

On the 12gaFH, I think perhaps 3 inches of rifling in the muzzle would make certain of the accuracy, since you won't be patterning shot. Any more than this, and it could start to slow the projectile down and increase recoil again. Also, if you're not firing shot, I'm not sure whether the choke effect would be required at all. A fully-rifled barrel, with the rifling honed out to within 3 inches of the muzzle, would be an easy option.

I have acquired a pair of rifled chokes to play with, and this is another option. For the 12gaFH they would probably need to be brazed in, for the kind of punishment you are planning to inflict! The Rem-choke rifled chokes I acquired last year are about .740 across the start of the forcing cone, though they squeeze down to .716 across the lands at the muzzle. This means that the forcing cone would be 'jugged' slightly in a .729 barrel. It won't worry me if I hone out to .736-.737 for my .735 Fosbery slugs. Some of the other rifled choke brands like Cation may be better, but its too big a hassle trying to get hold of them over here.

Cheers

A guy good build a screw on rifled section also,
like screwing on a muzzle break.Also with a longer bullet say with 2 or 3 grooves, you possibly could make a hollow base like Foster
slugs so that they would be nose heavy and might
be stable out to a hundred yards.Have the back groove shallower so as to have metal around hollow base.The ideal would to be able to do it without rifling with say a 3 groove hollow base
at about 1500 gr with a hollow base..Ed.

I was at www.mountainmolds.com a few weeks back and he showed me an 8bore slug from a mold he made. It sure did look impressive. I don't believe that he makes hollow base molds though. He has a very resonable price for most anything you could think of. He bores on a CNC lathe so custom profiles aren't a problem.
It may be worth looking at.

Here is a really sick idea! Thompson center makes 12 Ga barrels in 3" mag size for the encore action and E. A Brown offers screw in rifled chokes for them. Encore actions are extremely strong and will easily hold a .416 Rigby operating at 45 KPSI. Of course the back thrust of a 12 Ga shell will be much greater, but I'll bet a shortnened Rimmed .50BMG case in an Encore could easily meet the 30KPSI level. With a rifled choke and a properly fitted parradox bullet, this just might be a viable option for a 12Gga FH-Short. You could always tig weld two encore frames together and make a poor mans double.
Who has molds for paradox bullets?-Rob

[ 09-22-2003, 09:00: Message edited by: Robgunbuilder ]

Rob What if we got one or two riffled barrels and made 3" sections out of them for a screw in choke system. The barrel would have the same wall thickness and pressure would not be an issue.

John

I talked with www.mountainmolds.com and he said that his blocks don't normally go that large, but if there was enough interest that he could probably make a run of extra large ones.

I am concerned that health insurance policies are going to start having exclusions for injury incurred due to firearms recoil...

By the way, E R SHAW ( gasp) does make 12 ga rifled shotgun barrel blanks for about $125. We could cut them up for the 3" sections.
I'd be willing to go in for a mold for a paradox bullet. How much will Mountain Molds charge for one.-Rob

Fritz 454,
Will your action take an 8ga shell?
Switch barrel?
If not, what is the largest rim diameter she'll hold?

Thanks,
Matt

BMG- The plan is to take the paper drawings and put them on cad, that will allow me to solid model the action. Once that is done you can rotate the action virtually and scale it up or down as you want. It certainly can be scaled up to accommodate an 8ga case. I will have to wait for the scaled up version of the 12 ga FH to know if the 8ga will work.

What is the rim dia? The outside case dia and the length of the 8ga? As soon as I can I will let you know if the same action can be used.
John

Rob-Does the shaw barrel have the same OD as what you are thinking for the 12ga FH? If not we can always thread it into a piece of 4140 of the same OD so the contour matches. This will keep the effective strength of the barrel.
John

Fritz454- I thought we could turn down the shaw barrel sections and thread them. I'd then bore out a Pac-Nor barrel and internally thread for the 3" rifled choke. Is this what you were thinking?-Rob

Fritz454,
The following is from http://website.lineone.net/~dave.cushman/shotshellloads.html

8ga chamber specs:
Bore- .835"
Chamber- .930" (Rear) & .914 (Front)
Chamber length- 3.25" (Most) & 4" (Some)
Rim Recess diameter- 1.035"

4ga chamber specs:
Bore- .935"
Chamber- 1.090" (Rear) & 1.035 (Front)
Chamber length- 4"
Rim Recess diameter- 1.2"

FYI- Krieger makes barrels for the 4ga ( http://www.kriegerbarrels.com/product_info.php )
4 BORE CM 0.9360 0.9500 1~20 #12 E
and RMC could make the brass. Bullet molds are out there and any convience store carries Aleeve

Rob-That would work if when you to removed the rifled section you thread in a smooth bore section for the weight forward bullets. This would also work well for being able to add interchangeable chokes for shotgun usage.
John

BMG- I think this would all work. I'm not certain until I get some of the CAD work done. We're looking at a 1 1/2 - 14 tpi for the 12 ga FH so getting a barrel onto that platform for the sizes you indicated should be OK. I preface this by saying that you will not be running pressures up to the 12 ga FH vicinity but keeping them at normal shotgun levels.
John

I think that even a 4 bore would work on a 1.5 X14 tpi barrel shank. I'm in agreement with john , that at the normal operating pressures of a 4 or 8 Bore , you should be OK with this barrel shank dimension. You do have to watch the other action dimensions to ensure that the case can actually fit.
This is the problem with the Greener shotgun actions. A case longer than 3 inches physically can't be made to fit down the action without substantially weakening the breech block. -Rob

Fritz- Rob-Would you need an 1.5 in thread on
the scaled up action for 12GA FH.The barrels are that size.A 1.35 thread with 1.5 barrel give a
shoulder on barrel to torque to action.And that thread size scales up about 35%..Unless
we do it Savage style with a large torque nut,
which is fine with me.Makes headspacing and testing easy.

Rob-I got the Greener today.This one has the regular shotgun firing pin.What diameter firing
pin does a BMG primer need?Getting it apart and checked out.Ed.

Okay, sounds like we have some ideas to play with. I can do some encore testing, but I still need to get bmg based brass. I can also do some test with paradox brass. The brass i have is less than 10 years old and is machined as far as I can tell. The internal thickness of the base is almost .25" The web is kinda thin tho. If I can get some brass I can test in a fixture. The problem I see is that the breach of the encore is only 1" wide. The chamber walls are quite thin on the 12 guage barrel. I can also weld on a very thick 12 guage barrel on a 10 guage single shot. But I do not have any heavy brass or a way to make it. Somebody sell or trade me some brass and I will take what I have out and test. I think the 600 nitro bullet in the sabot is a interesting idea too. I also was planning from the start a smoothbore with a screw in rifled choke. I also have looked at the paradox setup available from Fabarm, but I am unsure as to the strength of the action.

I talked with www.mountainmolds.com today and he said that the 8bore fit the blocks because it was short and rounded. He said he might be able to fit a 900gn 12ga in his standard blocks. To fit a 12gaFH bullet in the block he would have to use a block without gooves for the handles and make an external mount for them. What bullet weights would you be looking for? 1000, 1500, 2000? You might drop Dan an email with more specifics. Is the Paradox bullet a hollow base?

ED- Firing pin diameter doesn't really matter much with the .50 BMG. You do need .065-.080 firing pin protrusion though and the primers need to be seated .007 deep and "armed" with a flat primer seating tool. At least thats what I do with CCI-35's. Keep the pins end rounded or it will pierce easily.
My Greener had the three prong firing pin breech block, so I drilled out the old slots and tapped it for 1/4X24 tpi hardened machine bolts. I then hi-force 44 soldered in the bolts and then milled the bolts flush with the breech block surface. The whole process took about 1 hr. It worked out beautifully. The Greener firing pins are hardened so use carbide to face the pin back so that you can get enough protrusion. Mine will fire a .50BMG primer, but just barely hits it hard enough. It really needs more spring. For Ha ha's I made a 20 ga shotgun shell adapter out of an old barrel stub and used it in the Greener this weekend. Worked pretty darn well too.
Barrels for the .50 BMG McBros actions are 1.495 Major thread diameter and 12TPI. However they have a large thread engagement area. For the Hi-wall I thought I'd keep the same 1.495 diameter but increase the threads to 14 TPI since the engagement area would be less. In reality, I think a 1.35 inch barrel would do just fine. I'd prefer the barrel to lock up on a shoulder rather than deal with a locking ring.
Pyronecko-I can make you a few rimmed cases using .50BMG brass for experimentation purposes. Your right the encore barrel looks pretty thin, but they are rated for 3"mag shotgun shells. I would not push it too far, but with good .50BMG brass it should still yield pretty impressive results. I'll bet 2000 fps with a 750 gr paradox slug and H50BMG or Rl-25 powder will be easily obtainable. Heck, I was shooting some 1 1/4 oz Brenneke slugs out of my M1 Benneli at 1600 fps out of 23/4 inch shells. EABCO has the rifled chokes for sale and if we could get some paradox slugs we could quickly test it out!-Rob

[ 09-23-2003, 09:44: Message edited by: Robgunbuilder ]

Rob--Thanks for the info.The firing pin on
this Greener protrudes .130, so I have plenty.
And I am glad you can make the brass for him,
as you have better, faster, machinery.As soon as
you and John get Hi-wall all figured, we can get Pacnor building barrels.I may have a way figured to go full length case in a beefed up, thick
side wall, larger reciever ring,
Greener.Ed.

Sonds like a deal to me I will need to get the brass at 3" to test in the encore. I will test the system up to the velocities I am trying to achieve or destruction, which ever comes first. I will use the TC factory turkey smoothbore barrel with a rifled choke. I will start with foster type slugs in ~750 grains and when we can get the molds I will go up to the 900's. My desire for this still is for the 900's at about 1800-2000 fps. When I achieve this I will be satisfied. I hope to eventually finish a double at around 9lbs in 12gafh light. I will continue to follow the quest for the 12ga from hell tho and when it is achieved will consider one to play with. I think the highwall will be the most atttractive finished product.