Case forming 7.65 Argentine from 30-06. Which die works?

I bought a RCBS case forming die for the 7.65 Arg for my 1891 Argentine. I formed the cases from WWC 30-06 new brass and then ran them thru a Lee sizing die. When I try to chamber a case the bolt will not shut. I have seen in older posts that the Lee die is for the Belgian & Argentine and that the Belgian chamber is a little larger. Unfortunately I managed to get two sets of Lee dies which I now cannot use. Are there any other dies made by someone that are only for the Argentine that will work without moding. I have seen where some one has shortened the Lee die and it worked but I don't think that I have the equipment to accurately do that or know of anyone that can do it for me.
Thanks

It's not an issue with the die per se. The hardness of the case in the area where the new shoulder is formed is harder than a neck/shoulder area is on a factory case. You can try annealing the case in this area prior to forming. Just be careful that you don't let the base get too hot. If you've never done annealing before, read up before attempting it.
Working the brass, ie: forming and resizing, hardens it. Annealing softens it. Only the neck and shoulder area should be annealed.

Or you can do this.
Take .005 off the top of your shell holder. Mark the shell holder for this purpose only. Use a good lanolin based lube like Imperial Sizing Die Wax.

You could also buy a set of the Redding shell holders that are in .002 increment different thicknesses, but they are pricey.
Redding Competition Shellholder Set #1 (308 Winchester 30-06

Finally, anneal the case necks when you are finished reforming them. They will crack if you don't.

Graf & Sons has new Prvi 7.65 brass for $60/100. After you reform/trim/anneal 100 cases, you will probably wish you just bought new ones.
Graf Sons - PRVI PARTIZAN BRASS 7.65x53 ARG. UNPRIMED 100/BAG

You may have to inside neck ream also as the case will be thicker there now. If you've seated bullets, it's like the snake that swallowed an egg...too fat. Also you will have to reduce the load by a bit because the remaining case will be thicker and not have as much inside case space.

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Originally Posted by no4mk1t

The hardness of the case in the area where the new shoulder is formed is harder than a neck/shoulder area is on a factory case.

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Why would this keep a cartridge from seating?

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Originally Posted by browningautorifle

You may have to inside neck ream also as the case will be thicker there now. If you've seated bullets, it's like the snake that swallowed an egg...too fat. Also you will have to reduce the load by a bit because the remaining case will be thicker and not have as much inside case space.

Why would this keep a cartridge from seating?

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Hard brass has a spring back property to it. This is what makes extraction of the case easy and why "cartridge brass" (70% copper/30% zinc) is used for cartridge cases.. Upon firing, the case expands and seals the breech, (its primary function) then the case contracts slightly and releases its grip on the chamber walls.
This same spring back occurs when reforming the case. You either have to push it slightly further into the die so after springback, the case will chamber properly, or anneal the area where the new neck and shoulder will be formed to make that area soft. The annealed area will then not spring back.
All in all, a lot of effort. You have to do it for antique arms where cases are no longer made, but if new factory brass is available at a reasonable price, it makes more sense to buy.

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Originally Posted by no4mk1t

This same spring back occurs when reforming the case.

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IE metal has a memory. Same as barrel straightening, go past the bend and then it returns to straight. I've been reloading most of my adult life and have had lots of obsolete stuff requiring case reform. For me, the cheapest way to effectively load makes thee most sense.

I still think he may have other issues to deal with.

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Originally Posted by browningautorifle

I still think he may have other issues to deal with.

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Maybe so. We will have to wait for him to report back and weigh in whether or not anything posted proved helpful. A cursory Google search indicates that he is not the only one having that issue reforming 30-06 to 7.65 though.
He may not have been aware that new brass was available and may abandon the attempt to reform them from 30-06. I would.

If you can't find "proper" 7.65 brass and have a little time up your sleeve, try forming these cases from 7.92 x 57 brass, new, preferably, and also available from our Serbian cousins.

Not nearly as much "extra" to trim off and any neck reaming will be somewhat less arduous than if the cases are formed from .30-06 brass.

The usual caveats about annealing (perhaps before and definitely after) still apply, though, if you want decent case life and "ease of working".

Shortening .30-06 cases was the norm back when the world was awash with ex-mil brass; sadly, those days are gone.

Are you lubing the inside of the case neck before running it through the sizing die? If not the expander may be stretching the shoulder enough to prevent chambering.
And I assume you're using a FL sizing die and not a neck sizer?
I never used a form die when converting 30-06 and similar brass to 7.65x53mm. I just lubed the cases good inside and out, ran them through an RCBS FL sizing die, rough trimmed, annealed, final sized/trimmed and loaded. Never had any not chamber or give any other troubles. I'm still loading some that I made up 25 years ago.
I preferred Remington or Winchester cases, Federal and military brass was thicker and sometimes required neck reaming.

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Originally Posted by vintage hunter

. . . I never used a form die when converting 30-06 and similar brass to 7.65x53mm. I just lubed the cases good inside and out, ran them through an RCBS FL sizing die, rough trimmed, annealed, final sized/trimmed and loaded. Never had any not chamber or give any other troubles. I'm still loading some that I made up 25 years ago.

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Yup, same here - except I never found a need to anneal these until after a half-dozen or so reloads. (Also never had brass so thick or chamber so tight as to need neck-reaming.)

https://www.milsurps.com/images/impo.../33upoog-1.jpg
US military .30/06 anneal extends far enough to include 7.65 shoulder.

I'd venture that mrappe's problem might be traced to press spring during the FL sizing operation, perhaps combined with inadequate case lube. This can be addressed by adjusting FL sizer down about 1/8+ turn beyond no-load shellholder contact, and using castor oil as sizing lube.

https://www.milsurps.com/images/impo...7/1f8uwz-1.jpg
Visible gap during actual sizing indicates die might need to be adjusted down to compensate for press flex.

I agree with Bruce, 7x57 & 7.92x57 are a lot easier to work with !...................