Wolf's loads for his 10.75x68 seem reasonable with his 400gr SP at 2100fps which about duplicates the old .404 load. I find it very hard to believe that 2300fps with a 400gr would be attainable in this rather small case. It would certainly be pushing the pressure boundaries and I would not like to use such loadings in early firearms chambered in 10.75x68.

Another point that has not been mentioned, although is recognized in other posts on case life, is the issue of the very slight shoulder that the 68 case has. As in the other posts and in particularly in reference to the 375H&H, shallow case shoulders tend to allow brass flow leading to very short case life. I imagine with the scarcity and cost of cases lower pressure loads would be the order of the day in the 10.75x68.

On the earlier query in this post about the velocities Von Gruff achieved from some old Kynoch rounds in his .404, I checked back in some notes and I see I did pull a Kynoch .404 round some years ago to see what and how much powder was loaded. This was a round from original sealed packets of five of the nitrocellulose “increased velocity” load with an advertised velocity of 2225fps. The cartridges are Berdan primed with purple sealer around the primer pockets.
The powder charge weighed in at 75.0 grains and most likely Nobels No 1. These cartridges chronograph at just on 2200 fps in my .404.