Frommer 1910 in 7.65 Frommer

[RetE8USN]

Anyone have any data on case dimensions? It is a rimless case and from what I have been able to find, is real close in dimensions to the 7.65 Roth-Sauer. Any leads on where to obtain brass already made for this ctg?

[Mk42gunner]

Just a wild guess, have you tried Fiocchi? They seem to make a lot of older calibers, however some don't normally get imported into the States.

Robert

[17nut]

https://forum.cartridgecollectors.or...-frommer/24469
https://forum.cartridgecollectors.or...oth-sauer/7201

[RetE8USN]

Tried Fiocchi - no-go
Looked at the links above - thanks for sharing them

[Adam20]

[RetE8USN]

Frommer 1910 7,65x13mm Frommer Short / 7,65x13mm Roth-Sauer Case Prep

With the lack of brass cartridges, new or once fired, or no available loaded ammunition, wanting to shoot this 108 year old pistol requires making your own cases. This is not an easy task and requires patience or you will ruin a lot of brass in the process.

From the specifications taken from an original 7,65x13mm case, the closest currently manufactured case is the 7,65mm Browning/.32 ACP. Review the specifications for the case dimensions in the picture below. The .32 ACP requires the Rim Diameter be reduced to .332 to .334 and the case length shortened to .515. Through trial and error, I found the following procedure to be the best for me…

My first step is to reduce the case length to .515 using the Wilson Case Trimmer before reducing the rim diameter. If you reduce the rim diameter first, the case will fall straight through the trim die unless you send them a sample case and they custom make you a trim die. I use a Wilson Case Trimmer with their .32 ACP Trim Die as the length of the die is short enough to get close to the trimmer head. Once you have the trimmer set, replicating the CL on following cases is easy, but time consuming even with their Power Adapter.

To reduce the rim diameter, not having a lathe, I use a hand drill and flat metal working file in medium and smooth cuts. Using trial and error, I have figured out how many passes it takes of the file to get the rim diameter close to what it should be. To get it to the proper diameter, I take the case out after a couple of passes of the smoothing file and measure. Time consuming and you need to keep the pressure you use on the file as consistent as possible. You will ruin a few cases. After the finish file I use 0000 Oil-less steel wool (like cabinet makers use) to polish up the rim.
During initial sizing tests I used a partially filed down rim to check against the bolt face to make sure the “factory” specifications would work and no-one had messed with the bolt face by opening it up to accept .32 ACP rims. The .32 ACP case would not fit in the bolt face. To get the maximum diameter of the case that would fit, while reducing the rim size, I stopped periodically and checked if the case would fit or not. When it reached the point to where the case would just barely fit into the bolt face I stopped and recorded that measurement as 0.336

After the forming of the cases is complete, I check each case for function. Making sure it fits in the bolt face properly, that the extractor fits and the case fits into the chamber and the bolt closes securely.

I took a couple of cases that were finished and primed them. Without a bullet in the case, I hand fed them into the chamber and let the slide close normally. The case locked up perfectly. I fired the pistol and the firing pin struck with sufficient force for detonation and a good strike mark on the primer. Load work up will be the next step. I will be using a med soft cast 77gr RN bullet (10 to 1 ratio pure lead to pure tin). Starting load will be 1.8gr Bullseye, WW small pistol primers. Max load will be 2.2gr Bullseye. Test loads will be measured by a chronograph to check the velocity to make sure I stay under the factory of 1100 fps. My goal will be the best accurate load under 1100fps.

Test loads completed: Settled on 2.0 gr Bullseye, Avg FPS was 936 with an ES of 32 and SD of 16. Very good group at 30 feet with no feed or extraction problems encountered.