30-06 pmvf/ccc

[arlon]

I just stumbled across and old (1938) Winchester 70 Target that was a 30 Govt. 06 and is now a 30-06 PMVF. It just looks similar to an Ackley improved. It chambers and fires a 30-06 and the result is a nice fire formed PMVF piece of brass. Am I missing something or can I just load some light red/blue dot loads, fire form a bunch of brass and hopefully be able to just neck size or maybe not even do that for cast shooting (thumb seat). Have not seen any dies available so the chamber has to be the die or the rifle has to be a wall hanger..

[Winger Ed.]

You can send off a couple of your fire formed brass to various die makers and they'll make you a sizing die through their custom shop.
It probably is a little pricey, but it's doable.

[arlon]

You can send off a couple of your fire formed brass to various die makers and they'll make you a sizing die through their custom shop.
It probably is a little pricey, but it's doable.

Probably more pricey than it's worth to me. Got the gun cheap enough I can part it out if I can't make a reload and make a cast bullet shooter out of it.

[Texas by God]

You can neck size and probably seat bullets with .300 magnum dies if done carefully.

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[376Steyr]

PMVF = Powell Miller Venturi Freebore, the predecessor to Roy Weatherby's double radius shoulders on his Magnum series. I bet if you check the throat on your rifle you will find the bullets will also have an exceptionally long jump before they touch the rifling.

[Winger Ed.]

Probably more pricey than it's worth to me. Got the gun cheap enough I can part it out if I can't make a reload and make a cast bullet shooter out of it.

Unless it's all beat up and worn out--- that's a lot of rifle to just part out.

[376Steyr]

Parting out a prewar Model 70 Target. [smilie=1:I think the OP is just messing with us. Like the guy on another forum who claimed he sanded off all the inspector stamps and put a shiny finish on the stock of his mint M1 Garand, just to rile up a snob of a collector who had annoyed him.

[arlon]

LOL, This rifle is a pretty early target. They were pretty interesting in some of the details that went into them. I don't get why someone had to rechamber it but they did. I'll figure out a way to make it work. Really nice and rare old rifle. I think they made less than a 1000 of them in 30-06. It also has a Pachmayr low-swing base on it (drilled and tapped with a bunch of holes) and nice Lyman target sights. I guess someone wanted to mount something other than a target scope on it. Oh.well. No mint collector but it should be a fun shooter and has a TON of "couch" appeal.

NO parts will be sold off of it. (-:}

[376Steyr]

I'm sure it was rechambered to get increased velocity from handloads over the standard 30-06. The venturi shoulder was supposed to let powder gas flow more smoothly (questionable) and the freebore allows more powder to be loaded as it essentially creates a larger chamber. Since pressure testing and chronographs were not readily available at the time, extra stout loads would be loaded and estimated velocity increases tended to be rather optimistic. Run a reamer into your 30-06 and get 300 H&H performance! What a deal!

[arlon]

I'll leave it as is. Barrel is stamped "30-06 PMVF converted by VARD pasadena" Hate to have to scratch that out and add 300 H&H even though 300 H&H is on my dream list.

[Winger Ed.]

VARD was a company out there that made various instruments like calipers and components for B-17s during the war.
So they'd have had pretty much unlimited machinist equipment, and master craftsmen to operate it.
It might have been done as someone's Lunch break project back in the day.

A buddy's father in law was a machinist in the late 40s and into the 70s.
He did scope mounts and bent the bolt handle on dozens WWII rifles over the Lunch hour in the old days.

[arlon]

PMVF = Powell Miller Venturi Freebore, the predecessor to Roy Weatherby's double radius shoulders on his Magnum series. I bet if you check the throat on your rifle you will find the bullets will also have an exceptionally long jump before they touch the rifling.

I'll say there is about 2 1/2" of freebore! Don't think will be a huge issue for cast but I also don't get the purpose. I'll have to do a chamber cast to get that diameter right. I think bullet diameter could be a big issue with that much freebore.

Maybe since they were probably trying to match 300 H&H performance the long freebore might help with pressure. Just guessing. Doubt it helped with accuracy.

[Jim22]

You can neck size and probably seat bullets with .300 magnum dies if done carefully.

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I have done just that with a .30-06 Ackley Improved. I bought a .300 Win Mag die and had a little turned off the base so it would size the whole neck. Now with shorter, '06 length, belted magnums available I'd prolly start with one of those. The seating die is not picky. I think I used a .338 Win. Mag. seater and everything was fine.

Jim

[725]

Any chance of a picture?

[lar45]

I wonder if you could neck size with a 300 WSM die?
Start with a chamber cast maybe, then compare to standard dies, should be able to make something work.

[Jedman]

Have you actually fired standard 30-06 in this rifle ? The reason I ask is the pic of the 2 casings you have side by side it looks as though the standard 06 longer shoulder slope would contact the neck portion of the longer necked PMVP chamber. Usually the improved chamber moves the shoulder forward with a sharper shoulder angle the picture looks as the should is moved rearward and the neck is longer.
It may just be a illusion with the picture ? Like others have said if you can find a 30 cal die with a similar shoulder it should work.

Jedman

[arlon]

It has been fired (by gunsmith) with factory 06 ammo. It is so close to an ackley improved it would be hard to tell them apart. Headspace is same as 06 so factory ammo can be used in a pinch.

I found a LEE universal decapping die that seems to work perfectly for punching the primers and doesn't touch the neck. Shooting cast I may not even have to neck size.

I did find the patent for these cartridges (with some help on another forum) that made for some interesting reading! https://www.freepatentsonline.com/2455080.html

Weatherby seems to have been influenced by them too. https://www.africahunting.com/threads/the-weatherby-connection.15735/

I'll try to get a few pictures up tomorrow.

[376Steyr]

I'll say there is about 2 1/2" of freebore! Don't think will be a huge issue for cast but I also don't get the purpose. I'll have to do a chamber cast to get that diameter right. I think bullet diameter could be a big issue with that much freebore.

Maybe since they were probably trying to match 300 H&H performance the long freebore might help with pressure. Just guessing. Doubt it helped with accuracy.

The theory was that upon firing, the long freebore would allow the bullet to immediately jump forward under low pressure until it contacted the rifling, where it would pause until pressure built up enough to drive it into the rifling and on its way. During that pause, space behind the bullet would act as an enlarged firing chamber, essentially increasing case capacity. This allowed the intrepid handloader to stuff a heavier than normal powder charge into a standard-sized case. The older Weatherby cartridges use a less extreme version of this system, with longer than currently fashionable throats which result in some bullet jump before the rifling is engaged.
If it was my rifle, I would try matching bullet diameter to the throat, hoping that everything would be aligned and square when it finally hits the rifling.

[TurnipEaterDown]

Freebore was/is not exactly meant to create a bullet jump & pause.
It is meant to reduce pressures at start/near start, and to allow the bullet to 'get a running start' before contacting the rifling where resistance rises.

This has a Similar effect that reducing starting pressure (release from case) does, but really isn't the same. Changing starting pressure can be toyed with on various simulation models to see what it does w/ peak pressure relative to powder charges.

A reasonable view is that these actions do increase the total available combustion volume at Peak pressure point in the combustion curve (the bullet is further down the barrel at peak pressure, given an equal charge of powder in the same size case w/ & w/o a large freebore).

While these features do alter the pressure curve, and can change achievable velocity, the old 'make a 30-06 perform like a 300 H&H' really had a lot to do with better powders after WWII & a 'load until it starts sticking, then back off 1 gr' approach. When you look at the 1930s performance of a 300 H&H, it isn't too much better than a 30-06 w/ 4350 under a 180 at max pressure, and if you push that 06 pressure to 65K psi it's even closer. Of course, what was always ignored is, you can use better powders in a 300 H&H than they had in the 1930s too.

In any event, hope you have fun with the rifle, and enjoy an oddball w/ history.

Lots of reasonable approaches to ginning up a die combination that will work, as mentioned above by others.
The older Hornady NS dies used to be made so that they didn't come close in diameter to the shoulder, if I remember right. I remember the same part number being used to NS a 300 mag & 30-06. I hope my memory is good on that.

[arlon]

Any chance of a picture?

Have a few. I think the only thing on this rifle that hasn't been cut, drilled or reamed is the original target trigger and it's pretty nice. It sure isn't a collector but I'm hoping it can at least be a grizzly beer can shooter with some funky history. I did find a set of rings for the old Low-Swing scope base.. (-:}

[CKent323]

My Grandfather was Edward Baden Powell (who also went by E. Baden Powell and Baden Powell). He and Ralph Waldo Miller co-invented and patented the Powell Miller Venturi Freebore (PMVF) design (patent 2,455,080 Nov. 30, 1948).

They accomplished this by rechambering an existing rifle to accommodate an oversized case machined to their design. They set up a company rechambering rifles and selling dies.

Interestingly, Roy Weatherby ordered a .270 PMVF based on the .300 H&H Magnum case, and he was so impressed he later asked Miller to assist in developing a new line of “magnum” cartridges to be used in custom-ordered rifles.

In the meantime, Powell and Miller sold their company to Hollywood Gun Shop. That company offered the same service but gave the concept a different label—the CCC (Controlled Combustion Chamberage) designation. Weatherby subsequently partnered with another machinist, and they produced the .375 Weatherby.

I know that Lyle Corcoran, who owned Hollywood Gun Shop, was an acquaintance of my Grandfather and his company made CCC dies but I am not sure if he rechambered the rifles or if that was done by another company. VARD is stamped on the rechambered firearms and I do not yet know if VARD, Inc of Pasadena, who produced drafting machines, calipers and other measuring equipment made them under contract of if there was another company named VARD that did the machining.

The CCC cartridge was available in many different calibers from the .218 Bee though the .375 H7H magnum including .219 Zipper, .223, .243, 250-3000, .270., 30-07, .300, 6mm, 7mm and others. I have seen CCC dies marked Hollywood Gun Shop and others marked RCBS (these may be the original PMVF dies).

My brother and I own Winchester model 70 rifles chambered in CCC. One is .300 CCC and the other is .375 CCC. We have dies for both made by Hollywood Gun Shop.

Neither of us has fired these rifles but my Father did when he was working for my Grandfather as part of E. Baden Powell and Sons. They did a significant amount of ballistics testing in the 1940’s and my Grandfather wrote a technical bulletin containing graphs and charts, based on the ballistics testing, entitled "Killing Power" which was published by the NRA in 1944.

E. Baden Powell had several other firearm inventions and patents mainly for shotguns (he competed in .410 and 12 ga trap and skeet and was well regarded). He is probably best known for the invention of the Power-Pac which was marketed and sold by his friend and bsiness partner Frank Pachmayr of Pachmayr Gun Works.

The information here on the PMVF and CCC was corroborated, and some details filled in by, the following articles:

“.375 CCC Reloading Data” by Lane Pearce, March 18, 2019 - Shooting Times

“Don't Be Afraid of an Obscure Cartridge: The obscure .375-CCC wildcat round is eerily similar to and has a historical connection with the .375 Weatherby Magnum” by Lane Pierce Feb 9, 2019 – Shooter’s Gallery: THE RELOADER

[CKent323]

Doing a bit more searching I found the an article entitled " The Weatherby Connection" by Wayne van Zwoll on the development of the Weatherby cartridge.

https://www.africahunting.com/threads/the-weatherby-connection.15735/

He asserts that VARD was the name of the company that Powell and Miller formed (I am not sure that is correct). Here is an excerpt from the article:

"While the subsequent success of Weatherby rifles resulted mainly from Roy’s hard work and brilliant salesmanship, his early magnums probably owe a great deal to fellow Californian and wildcatter R.W. Miller. In 1940 Miller was loading the .300 Hoffman, dropped from Western Cartridge Company’s line seven years earlier. Western claimed the steep Hoffman shoulder hiked pressures, and that, loaded to acceptable limits, it wouldn’t exceed the velocity of the parent .300 Holland.

Miller figured if he replaced the angular neck junctures with rounded, or radiused ones, powder gas would flow more smoothly, directing more energy at the bullet base. This done, he lengthened the throat to reduce pressures as the bullet accelerated. After he wrote letters to The American Rifleman about his work, the magazine sent authority E. Baden Powell out to take a look. Powell advised Miller to straighten the case body, reducing bolt thrust and preventing premature escape of powder gas. The new cartridge was called the PMVF: Powell Miller Venturi Freebore. In 1944 the two men went into business under the shingle of Vard, Inc. But short of money, they sold in 1945 to Hollywood Tool and Die, which renamed the cartridge CCC: Controlled Combustion Chamberage.

About this time Roy Weatherby carried a .270 PMVF on a deer hunt and liked it. Weatherby asked Miller to help put the radiused shoulder on his rounds. Miller demurred. Roy went next to George Fuller, a machinist friend who had fashioned the reamer for Weatherby’s .220 Rocket. Fuller countered that a radius at the base of the shoulder would be hard to tool for – but he capitulated. Weatherby followed with a marketing package that would bring his venture lasting success."

[dverna]

Interesting read

[littlejack]

Just out of curiosity, does anyone have dimensions for the 30-06 PMVF case compared to the 30-06 AI case. Seeing as how both of the cartridges headspace on a factory round the same, and if the case dimension at the junction of the shoulder and case body are the same, or very close, a 30-06 AI sizer die may work if adjusted correctly.

[BrassMagnet]

This may come out of left field, but ask CH4D if one of their 30-06 improved sets would work well enough. They seem to have every possible angle of improved there is for 30-06.

[mdatlanta]

This was/is an interesting read and insight into a bit of firearms history. Thanks for posting, everyone!