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

[mrappe]

The bullets are now seating straight as I have used the decapper-expander and have adjusted the seating die to crimp enough in the crimp groove but the rounds are just a little tight when extracting/turning the bolt (only when a bullet is seated otherwise with a empty case they go in and come out easy). They go in just fine with a bullet seated but are somewhat tight when removing. I measure the neck with bullet against a factory Norma loaded round and the ones I make are a little wider. I think that it may be due to thicker brass in the neck.

[Mytmousemalibu]

The bullets are now seating straight as I have used the decapper-expander and have adjusted the seating die to crimp enough in the crimp groove but the rounds are just a little tight when extracting/turning the bolt (only when a bullet is seated otherwise with a empty case they go in and come out easy). They go in just fine with a bullet seated but are somewhat tight when removing. I measure the neck with bullet against a factory Norma loaded round and the ones I make are a little wider. I think that it may be due to thicker brass in the neck.

I'm nowhere near my reloading bench right now but if memory serves me right I was using a .309-.310 reamer? Enough just to buzz a little brass out of the neck. Measure your expander ball, a reamer the same size should work, thats what I did but I do have an assortment of reamers so I may have gone a tad bigger from that size if any since we are dealing with some spring back in the brass.

[mrappe]

I am looking at getting a outside case turning tool. I haven't found a reamer for this size. I am assuming that I can achieve the same results by turning the outside.

[Mytmousemalibu]

I am looking at getting a outside case turning tool. I haven't found a reamer for this size. I am assuming that I can achieve the same results by turning the outside.

Yup, a standard case neck reamer will do you just fine too. I will eventually need to get one, someday I won't have the right one!

[mrappe]

Good News:
I recieved the Lyman die set that I ordered in 7.65 Argentine and tried a case with it after using the RCBS case forming/trim die and trimming the case. I loaded the brass with a bullet using the Lyman seating die and it chambered and extracted easily. It looks like I will not need to turn or ream the case neck after all.

[mrappe]

One case worked in the Lyman Die but the case was not going al of the way into it. The next case got stuck in the die and when I tried to lower the ram the case rim sheared off. I had to dig the case out and the expander's threaded rod got bent. It looks like I will need to turn the outside of the neck to get it to work. I ordered a Forester hand held neck turning tool since they were the only one that I could find with a 311 mandrel for.

[EDG]

Copied from another forum

When the Lee 7.65 dies first came out people found they are too long in the body so they will not size a case that will fit a 7.65 Argentine Mauser chamber.
The following is an investigation of the dimensions of my rifle chambers, reloading dies, factory ammo, factory brass, resized cases and a few fired cases and etc.

I have 4 rifles - 3 M1891 and a 98/09 .
This is what the chambers measure using a .375 diameter gauge ring in a Hornady (headspace is their name for it) gauge attached to my calipers. The set up was corrected to zero with a 7X57 gauge to minimize any shoulder angle and chamfer issues found on the tool. You will see that I cross checked these number several ways to avoid any silly errors.

This is the dimension (for each of the 4 rifles) from the bolt face/case head to the gauge diameter on the shoulder of cases that barely drag when the bolt is closed.
1.822
1.821
1.820
1.820

AMMO and virgin brass
PPU ammo measures 1.819 to 1.821. It is excellent for my rifles. This ammo might NOT chamber in a CIP minimum chamber
New PPU unfired brass measures 1.818. Ditto
New Norma factory ammo measures 1.812 to 1.816 (more variable and a little shorter than the chambers) You can see below that it more nearly matches the CIP minimum drawing
New Norma unfired brass measures 1.815 ditto for the Norma ammo comments

Reloading dies
These sizes were all taken with the FL sizer or trim die down hard againt the shell holder. The same shell holder was used for all the dies. The shell holder measured exactly .125 deep.
Each case was cycled in and out of the dies 4 to 6 times without an expander until I thought the brass was not moving the shoulder back any more. At the end of each sizing stroke I let the ram dwell in the up position for 3 to 4 seconds so the brass had time to creep and take a set if it was still moving. My goal was to duplicate the inside length of the die as exactly as possible using FL sized brass.
Most of the cases formed were commercial once fired .30/06 that had been trimmed. If you cycle your brass only once during FL sizing it may be .002 longer than my results. I was using a RCBS Rockchucker press.

The Lee FL sizer measures 1.838" using the same .375 gauge diameter on a FL sized case. This is way too long - about .018 to .020 too long.

I have 2 RCBS FL sizer dies that measure 1.818 and 1.819. Just right in my opinion for my chambers.
I have another RCBS die - this one is a trim die and it measures 1.816 - Again RCBS gets it about perfect.

I have a modern Lyman FL die (less than 10 years old) an it measured 1.814 - a little bit short but....more later

I have a set of older Pacific dies and they measure 1.797 - not even in the right ball park avoid these at every opportunity. They are way the heck to short - even dangerous.
I have an old CH trim die that measure 1.781 - even worse. These cases might separate when fired. This die was not made by the current CH die company but it predecessor

Gages drawings and headspace gauges
I also have a Wilson Case 7.65 Mauser case gage that checks from the head to the shoulder. Wilson gauges are well known for exacting accuracy. My formed cases agreed with the Wilson tool and it agreed with the RCBS dies. Other Wilson gages also agreed with my Forster headspace gauges in several other calibers mentioned below.

There are no SAAMI documents for this cartridge but there are CIP drawings. The only problem is the CIP drawings are dimensioned using a different datum structure and they are not toleranced.
Therefore I took the Minimum CIP chamber drawing and used the conventions for SAAMI GO, NO GO and Field gages and applied them to the CIP minimum drawing.
To get the dimensions to the .375 gauge ring I had to create a spreadsheet that could calculate the SAAMI numbers from the CIP numbers because the geometry that locates the shoulder is defined in a different manner.
To test my spreadsheet trigonmetry I double checked some of the CIP drawings for American loaded rounds against the SAAMI drawings.
The test drawings included the 6.5X55 Mauser, 7X57 Mauser and the 8X57 Mauser. I got exactly the same numbers. I used those three because I also have a Wilson case gage for each and a set of Forster headspace gages for each. I can tell you that the Wilson Gages, the Forster go gages and my numbers agreed exactly to within .001. They are even better when comparing with a .0005 dial test indicator.

Here are the numbers for the CIP 7.65 drawings

Minimum chamber 1.816 I called this the GO gage length. This is the number calculated directly from the CIP MIMIMUM Chamber drawing. This seems to be the target for the Lyman FL die.

No go chamber 1.820 I just added .004 for the NO GO (If you add .005 the number is 1.821 for some SAAMI gauges the steps are .005 but I prefer .004) Seems to be the target for the RCBS dies.
Field chamber 1.824 I added .008 to the min chamber (If you add .010 the number is 1.826)

I have used my personal judgment in the No Go and Field dimensions. If you prefer you can use your own numbers.
My goal was to determine all I could from my dies, my ammo, my brass, my chambers and the existing standard CIP drawing.
Since I control my ammo head to shoulder dimension when I reload it I know what dimension to make it to fit my rifles.

I also know what dimensions Norma and PPU ammo and brass are produced at.
I also measured 2 of the SF 81 Argentine military cases at 1.820. Both of these cases seemed to have the wrong shoulder shape and chambered tightly in my rifles.

For my rifles I will load with the head to datum length set at 1.821. If that is too tight for the two tighter rifles then I will load them at 1.820.

Finally case length over all

CIP Min is 2.110 CIP max is 2.114

My chambers measure around 2.125 I will trim my cases when they are longer than 2.122. I get a little bit longer neck this way.
There is no danger from this. If the case if FL resized, when it is fired it will shorten .004 to .007. It will lengthen when resized. Always check your cases for over length each time they are reloaded if you decide to leave them long.

If you have one of the Lee dies that are too long you can get it cut off so it produces brass to fit your rifle.
You should have the capability to measure your chamber and your die before modification. Otherwise you are going to be doing a cut and try process that may not work so well if you are not careful.

You can also complain to Lee and see what they say.

From my measuring and checking RCBS dies are the way to go.

[Larry Gibson]

The problem is the Lee dies are for the 7.65 Belgian cartridge and are very clearly marked as such. The RCBS and Lyman dies are for the 7.65 Argentine cartridges and are marked as such. It has been assumed for many years the two cartridges were interchangeable because someone once said the 2 cartridges are the same and it has been repeated over and over so it must be so(?). The problem is the Belgian 7.65 chambers I have measured (using the same .375 bushing on fired and formed cases to measure headspace EDG used) have all been close to .010" longer than the respective Argentine 7.65 chambers. Interestingly the few actual 7.65 Belgian cartridges I've found were on the shorter size and would chamber (had 5 rounds of one lot that were a very tight crush fit though) in 7.65 Argentine rifle chambers.

I don't know where Lee got the dimensions for their 7.65 Belgian dies but if it was from actual 7.65 Belgian chambers I can see why there is a problem with their dies not sizing cases correctly for the 7.65 Argentine chambers because the headspace is shorter in the Argentine chambers. The problem with using the C.I.P. chamber drawing is that they list as the the 7.65 Argentine with the "Country of origin" as Denmark. C.I.P. lists the minimum chamber dimensions from head to junction of the shoulder and neck (L2) as 47mm which is 1.847". I have some actual Belgian 7.65 and the measurement from the head to the same shoulder/neck junction is 1.860"; some .013" longer. Case fired in my M91 Argentines measure the same dimension at 1.847:: just what it is supposed to be for the 7.65 Argentine.

Lee, in Modern Reloading, 2nd Edition, shows the same "L2" dimension as 1.876". Lee also shows a .375 datum at 1.842 for headspace. Thus it definitely appears to me C.I.P. has the correct dimensions for the 7.65 Argentine cartridge and chamber. It also appears to me Lee took their dimensions from an actual Belgian chamber/cartridge drawing or from actual 7.65 Belgian cartridge cases which has a longer headspace dimension than the 7.65 Argentine cartridge. That is why most cases formed with Lee's 7.65 Belgian dies will not chamber in most 7.65 Argentine rifles.

Larry Gibson

[mrappe]

Excuse my ignorance but what is CIP?

[EDG]

CIP is the European standards organization for firearms and ammunition

https://en.wikipedia.org/wiki/Commission_Internationale_Permanente_pour_l%27Epre uve_des_Armes_%C3%A0_Feu_Portatives

You may have to click the Union Jack to switch the language to English if you go to the CIP web site
This is the page for the 7.65 SArg. Mauser
http://www.cip-bobp.org/homologation...-en-page50.pdf

Either JGS of Coos Bay Oregon or Iver Henrickson had an old drawing from Winchester when Winchester made a few 7.65mm Mauser M 70s.
The drawing had a handwritten note that the 1891 rifles had a .010 longer chamber. Refering to hand written notes on any drawing is pretty poor configuration control. The DE reference for the origin of the 7.65 refers to Deutschland (Germany)

The Lee dies are easy to fix with a lathe and a few measuring instruments.
Measuring to the corner of the shoulder is not recommended. The location of the shoulder often can only be accurately determined with an optical comparator.
Even when you locate it the position may be due to differences in the shoulder angle as well as the length. That is why CIP uses the junction cone measurement and SAAMI uses a gauge diameter.


https://en.wikipedia.org/wiki/7.65%C3%9753mm_Argentine

If you look long enough you will find that CIP admits the 7.65 Mauser is one of a group of problem children with the delta L problem.
The maximum cartridge is actually longer than the minimum chamber according to CIP - even though their drawing has no tolerances for you to analyze.
If you read the wiki article about the Delta L problem you find many other cartridges on the list.

https://en.wikipedia.org/wiki/Delta_L_problem

I am not sure why the Belgian Mauser name is even used since there are so many more Argentine and Turkish Mausers in 7.65 Mauser in the US.
However RCBS uses "Belgian" and makes dies that work in Argentine rifles. Lee uses the same name and the dies do not work in Argentine rifles.

If you buy RCBS dies you will never be aware of of the confused dimensions or the Delta L problem.

If you buy another set of dies they may be either too long or too short and cause you a lot of grief.
However the Argentine rifles seem to be very consistent and are the ultimate gage of the ammo. Just make the ammo fit your rifle.

It is interesting that the last company to get CIP approval to manufacture 7.65 was PPU and their ammo is almost a perfect fit for Argentine rifles - at least is is for mine.

[mrappe]

I just got a RCBS die for the 6.65 Arg and it seems to do the trick. Now my chamber easily.

[Larry Gibson]

Excellent; die made for the right cartridge.

Larry Gibson

[leadman]

Larry, Many years ago I bought some "surplus" 7.65 Mauser from J&G Sales here in Arizona. It would barely chamber in my 1891 with quite a bit of pressure used to close the bolt. I found out later this was not actually military surplus ammo but was made on the worn Argentine loading machine and the dimensions were off.
I wonder if Lee had gotten some of this ammo to use in designing their dies?

[Larry Gibson]

leadman

Are you sure it was Argentine made? Do you remember the head stamp? If actually 7.65 Mauser it should have been a little difficult to chamber in my experience. Also there was contract ammunition made for Peru (I think) by FN which could possibly be the same 7.65 Mauser ammo I tested(?). That ammo has Spanish and Belgian on the packages. The bullets in those was .313. Does the book mention when Argentina started making it's own M1909s and/or the 7.65 Argentine ammunition?

Larry Gibson

Attachment 145497Attachment 145498

[blastit37]

A little off subject but...what do you use for a seating die? I have a RCBS die but it only will seat to .004 r.o. I would like to get down to at least .002. I use PPU cases and the r.o. no more than .001 at the neck when resized. Is there a better choice?

[EDG]

You might look for an old set of Bonanza 7.7 Jap Benchrest dies. The seater sleeve might be a little long but you can cut the bottom of the seating sleeve off a little and use it for a 7.65. My rifles are only have the issue sights so I just check my ammo by rolling it on a smooth flat surface. With practice you can see .003 TIR and set those aside.
I have a RCBS competition seater with a Vickerman type sleeve and the micrometer adjusting top. The bullet sleeve is large enough for .311 bullets. I have never tested the RCBS die so you might want to talk to some people that have experience with it. Because of its design it will work with any .30 cal from .308 to .300 Win mag. If you chance the sleeve and the seater punch you can load other calibers too.

A little off subject but...what do you use for a seating die? I have a RCBS die but it only will seat to .004 r.o. I would like to get down to at least .002. I use PPU cases and the r.o. no more than .001 at the neck when resized. Is there a better choice?

[paul edward]

From 1963 until 1975 I loaded 7.65 for an 1891 Argentine Mauser using RCBS dies and had no problems. After the 91 was stolen in 1973, I got a 1909 as a replacement. Unfortunately the 09 was not in good condition and had a dark bore. It would chamber and fire my reloads but and was not accurate. I gave up on it and had it rebarreled in .308 Winchester and I carved a new sporter stock for it. Was able to use my old brass by trimming, resizing and fire forming.