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. 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/thread...nection.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.. (-:}