7.65 Browning vs. 32 ACP

CIP 7.65 Browning
https://bobp.cip-bobp.org/uploads/tdcc/tab-iv/tabivcal-en-page12.pdf

SAMMI 32 ACP
https://saami.org/wp-content/upload...FP-and-R-Approved-2015-12-14-Posting-Copy.pdf

I have an old CZ-70 marked for 7.65 Browning. I finally found a reference shown above for 7.65 Browning, not 32 ACP. They actually show a .309 bullet diameter, not the .3125 shown in the SAMMI specs.

I actually ordered some Berry's that are .312 and 71 grain to try reloading for this, and not sure they are the correct spec, since everyone on the net seems to say 32 Auto and 7.65 Browning are the same, these references seem to show different. I haven't looked through all the other dimensions to look for variations, but I anticipate there are other variances. The bullet diameter seems to be a big one.

I'll have to pull out some factory ammo and do some measurements. .0025 over in bullet diameter seems like a lot. I'm pretty new to reloading, but if the spec is .001 over to bore for standard bullet sizing, the excess diameter to bore spec, then would be 250% additional diameter than the .001, and that seems like a lot when I look at it that way.

CIP chamber mouth H2 1) = 8.55/.336
SAMMI Chamber mouth 8.61/.338

Yea, the chamber dimensions also show a .002 difference. So, what impact would using a bullet that is .0025 larger than the correct spec cause?

Is there a source for .309 bullets for this at 71 or 73 grains? I haven't been able to find any.

Thanks for posting that from the Lyman manual. I have 5 reloading manuals and a team of reference materials and only 1 has anything for 32 ACP, and no mention of 7.65 Browning. I ordered a small manual specific to 25 and 32 ACP, to see what they collected there for info. I still haven't been able to find anyone who makes a basic drop in case gauge for this cartridge; guess using the firearm's chamber should work.

in additional to the different spec for bullet diameter and chamber, also it appears pressure and the cartridge rim are notable variances.

https://en.wikipedia.org/wiki/.32_ACP
"In Europe, where the round is commonly known as the 7.65 mm Browning, and features different rimsizing from the American .32 ACPs"

the maximum average pressure - as measured by a transducer on the test barrel - is 20,500 psi (1,410 bar) according to SAAMI, while CIP allows up to 1,600 bar (23,000 psi)

I guess this goes back to basics. If your firearm says 32 ACP stamped on it, use that - and if your firearm says 7.65 Browning - make sure the box actually says that. There's endless threads out there of people shooting old Euro guns, that don't work well at all with 32 ACP, so with that - they are not interchangeable, certainly not in actual application. Guns labeled 32 ACP, you may end up shooting ammo that is over the pressure rating if you load it with 7.65 Browning.

So, they are the same - sort of. At least the cartridge only uses like 2.2 grains of Win 231, so - the power there is relatively small compared to other cartridges.

fxvr5 said:

I think that trying to make the case that they are two different cartridges is an over-reaction.

Speer's manual indicates it has 2 names, but does not warn that one has more/less pressure. They say the some guns loaded Speer's 60 grain bullets might not run reliably in some European guns, as that they are designed for heavier bullets - so a difference in recoil impulse and how the guns are sprung.

Hornady and Sierra recognize 2 names for the same round. Nothing else. No separate load data. No separate pressure limits indicated.

I think if there was a difference, they would say so.

In other words, don't make stuff up. This is how BS internet rumors start. Unless you have specific information from folks in the firearm/ammo industry, be quiet.

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I'm not making anything up, you can look at the measurement published by the standards organizations; the links are posted above.

All I'm trying to do is figure out what components I can use to make hand loads for a CZ-70 marked 7.65 Browning. I don't know where to find reloading components that meet or are based on the CIP Specs the firearm was designed for. I have 3 Speer Manuals and a couple other major name reloading manuals and only one of them, an old Hodgdon's even references 32 ACP, none of them make any reference I can find at all to 7.65 Browning.

Now I'm thinking I should just hit e-bay and try to find European reloading manuals and component distributors, looking at US sources of info seems to be pretty much a fail so far as I can tell, and I'm pretty good at doing research. My understanding is the cartridge was vastly more popular across the pond, so - seems like a good next step.

What brass to use outside of factory European brass is one of my major concerns. Factory ammo labeled 32 ACP, with no mention of 7.65 browning seems to nosedive every 4th or 5th round, and stovepipe once every couple magazines. The nosedive as I've discovered seems to be the cut of the extractor groove being different, and with the semi-rim sitting in the extractor groove, simply seems to not sit correctly in the magazines resulting in nosedives and FTF issues. Boxes marked both 32 ACP and 7.65 Browning seem not to do this.

There are plenty of threads out there where people have issues running 32 ACP ammo in European produced surplus guns, and the common refrain is to use Fiocci, Geco, or S&B factory ammo as it is a little hotter which seems true, but I don't think from my experience - this is the actual root of the problem with running 32 ACP ammo in a firearm labeled for 7.65 Browning. The bullet size and chamber are also slightly different, and the extractor slot being a little different, also kind of a big deal in how the rounds sit and ride in the magazines.

So, it is pretty well documented that there are issues that can come up with the little variances between the standards (on the internet, but not in any reloading manuals I've seen) - and it is a pretty easy solution to run Fiocci or another box of factory ammo that says 7.65 browning on it, pretty easy.

What reloading brass, bullets, dies etc. This is where it seems to get dicey to me. I'm going to anticipate the dies will work, I actually think the Lee ones say 7.65 as well as 32 ACP, I got the RCBS ones - with no mention of 7.65, but I'll bet they work. Some brass will not really work for my application and find no source of brass referencing 7.65 Browning for sale. I see on the Fiocci website they appear to package unprimed brass for this cartridge, but I don't actually find it through a distributor.

For someone new to reloading, the firearms industry seems kind of challenged - in terms of producing data that is consistent and makes sense. You kind of have to play, put all the pieces together and then use your own judgement to make sense out of difficult and jumbled information - and there is contradictory information from various sources - not even for just this cartridge, for one as common as .38 Special. For .38 Special, one can look up a load on a powder manufacturer's website - and a bullet manufacturer's website, for the same bullet weight and type - and no matter how you look at it, the ranges are so different in the load data - you're 100% going to be either loading too high or too low, as the specs on load data have such a wide range. For someone new to reloading, that seems insane and honestly kind of dangerous, for all the times safety is reference in the manuals. If you follow all the load data, and safety precautions, you can't load the cartridge ever - because there is a current reference published today - right now, that says no matter what load data your using, it is outside of the safe range from another reference. Not very impressed with the "firearms industry" for that little bit of fun.

fxvr5 said:

The data in loading manuals makes perfect sense. You're confused by it because you're new to this and you have no clue about how all this works. You have zero experience and yet somehow, you seem to know more about loading ammo than the people in the firearms industry who test and measure pressure.

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So, feel free to share how you select from two sources of data that do not align with one another. Are they both right, both wrong, do you do an average between them or 3 or 4 if there are multiple sources of data, start with the lowest load data published? I certainly don't know.