Quote:

---

That cartridge is extremely rare. Von Hofe developed a number of Super Express cartridges including a similar 7x66SE. I wonder what the ballistics of the 7x73SE are.

---

Me too, on the 7x73 SEvH. Not the rimmed version. In some images it appears to be a magnum based cartridge? And what is its parent brass? And what ballistics?

--------------------
John aka NitroX

...
Govt get out of our lives NOW!
"I love the smell of cordite in the morning."
"A Sharp spear needs no polish"

Post Extras:

Quote:

---

Quote:

---

That cartridge is extremely rare. Von Hofe developed a number of Super Express cartridges including a similar 7x66SE. I wonder what the ballistics of the 7x73SE are.

---

Me too, on the 7x73 SEvH. Not the rimmed version. In some images it appears to be a magnum based cartridge? And what is its parent brass? And what ballistics?

---

A caveat first: All “vom Hofe Super Express” ballistics were published well before chronographs were widely available. Apparently they were established by shooting from 40” barrels over a typewriter. Noone ever came close to the advertised velocities when shooting v.Hofe factory ammo from a real rifle over a modern chronograph.
The 1931 7x73 v.Hofe SE was advertised with an 11 g = 170 gr “Torpedo Stopring” bullet at 1004 m/s = 3294 fps. The 7x73 was essentially a necked-down .300 H&H, though with a slightly larger, .3 mm, base (about the same difference as .30-06 vs. 6.5x55 SE). Due to it’s overall length the 7x73 required the use of a true commercial Mauser Magnum length action. BTW, all the known “Original v.Hofe” rifles were made for them by Christoph Funk, Suhl.
Post-WW2 Walter Gehmann aquired the “vom Hofe” name. When rifle and ammo making was allowed again in the 1950s, true Magnum length actions were unavailable. So in 1955 Gehmann simply copied a prewar experimental cartridge, the 7x66 Brenneke Maximum, and offered it as the 7x66 vom Hofe Super Express. This case is based on a .404 with a slightly rebated rim. The shorter, but fatter case has the same volume as the 7x73, but can be fitted into a slightly opened up Standard length Mauser action. Gehmann advertised it as providing he same ballistics, a 11 g bullet at 1004 m/s.
Pressure tested 7mm SE vom Hofe loads published by the DEVA don’t even get close. The fastest 170 gr loads don’t exceed 890 m/s = 2920 fps. To break the 1000 m/s within the max pressure of 4400 bar, you have to use 8 g = 123 gr or lighter bullets.

Post Extras:

Quote:

---

A caveat first: All “vom Hofe Super Express” ballistics were published well before chronographs were widely available...........
So in 1955 Gehmann simply copied a prewar experimental cartridge, the 7x66 Brenneke Maximum, and offered it as the 7x66 vom Hofe Super Express.
This case is based on a .404 with a slightly rebated rim. The shorter, but fatter case has the same volume as the 7x73, but can be fitted into a slightly opened up Standard length Mauser action. Gehmann advertised it as providing he same ballistics, a 11 g bullet at 1004 m/s.
Pressure tested 7mm SE vom Hofe loads published by the DEVA don’t even get close. The fastest 170 gr loads don’t exceed 890 m/s = 2920 fps. To break the 1000 m/s within the max pressure of 4400 bar, you have to use 8 g = 123 gr or lighter bullets.

---

Post Extras:

Quote:

---

Quote:

---

A caveat first: All “vom Hofe Super Express” ballistics were published well before chronographs were widely available...........
So in 1955 Gehmann simply copied a prewar experimental cartridge, the 7x66 Brenneke Maximum, and offered it as the 7x66 vom Hofe Super Express.
This case is based on a .404 with a slightly rebated rim. The shorter, but fatter case has the same volume as the 7x73, but can be fitted into a slightly opened up Standard length Mauser action. Gehmann advertised it as providing he same ballistics, a 11 g bullet at 1004 m/s.
Pressure tested 7mm SE vom Hofe loads published by the DEVA don’t even get close. The fastest 170 gr loads don’t exceed 890 m/s = 2920 fps. To break the 1000 m/s within the max pressure of 4400 bar, you have to use 8 g = 123 gr or lighter bullets.

---

kuduae,
I've never heard of the 7x66 Maximum cartridge by Herr Brenneke - do you perchance have any more info on this one or any other oddballs that he played with besides the x64 series cartridges?
Regards

---

I posted links on it, and there have been NE threads on it as wel - linked to that as well.

Kuduae may have posted on it already, if not, if he is willing, always great to see his comments add to our archived knowledge here. His comment on the 66 here provided new info, suhc as being developed to replace the eralier cartridge.

--------------------
John aka NitroX

...
Govt get out of our lives NOW!
"I love the smell of cordite in the morning."
"A Sharp spear needs no polish"

Edited by NitroX (27/07/21 12:32 PM)

Post Extras:

Quote:

---

kuduae,
I've never heard of the 7x66 Maximum cartridge by Herr Brenneke - do you perchance have any more info on this one or any other oddballs that he played with besides the x64 series cartridges?

---

Post Extras:

Quote:

---

Quote:

---

kuduae,
I've never heard of the 7x66 Maximum cartridge by Herr Brenneke - do you perchance have any more info on this one or any other oddballs that he played with besides the x64 series cartridges?

---

Wilhelm Brenneke experimented a lot with .404 base cases, read W.B.Dixon’s “European Sporting Cartridges”. About 1925 he designed the 9.3x70 for DWM. The 1934 DWM catalog only listed it with 18.5 g = 285 gr bullets at 845 m/s = 2770 fps, 17.0 g = 262 gr at 854 m/s = 2800 fps, 15 g = 231 gr at 905 m/s = 2969 fps. As that large case with the powders and primers then available produced unreliable ignition in cold weather, it was soon discontinued before WW2. Brenneke designed the 9.3x64 instead.
In 1937 Brenneke experimented with his 9.3x64 case necked down to his first 7x64.5 Brenneke Maximum. A year later he experimented again with the .404 case, now shortened to 66 mm and the rim slightly rebated. He created a 7x66, a 8x66 and a 9.3x66. The 8x66 Brenneke Maximum only was assigned a DWM case number #598. None of these experiments ever reached commercial status. So ballistics are unknown. Brenneke collaborated closely with DWM in developing his cartridges and loads. As Walter Gehmann worked for DWM at that time, he was certainly aware of Brenneke’s ideas and experiments.

---

Thank you kuduae!
Finding that book will be a mission in itself, but I now have a great reference point to search from thanks to you mate!
It is amazing what Herr Brenneke did in his lifetime, he certainly was way before his time. Shame the 9.3x64mm was never promoted more or pushed harder for commercial use, it really is a brilliantly efficient cartridge (along with all the other x64 series rounds).
Kind regards
93x64mm

Post Extras: