After receiving several emails on this neat little big bore requesting I do a post on it and furnish some loading data I decided the requests had merit as it is a little known caliber..It is very hard to find much printed data on this fine caliber.
My association with the 10.75x68 began some years ago with the purchase of a cute little Mauser 98 in that caliber, I found some brass, and bullets were available as it was a .423 bore ala the .404 Jefferys..It had some interesting balistics in that it duplicated the orginal specs of the .404 Jeffery with a 400 gr. bullet at 2100 plus FPS, and I reallized it had the potential to push a 350 gr. Monolithic (GS Customs in my case) to perhaps 2350 FPS and thats buffalo medicine in anybodys books..To top it all off the neat little round could be made in a 8 or 9 pound o rifle and not be a slobber knocker in recoil..
What more could a buffalo hunter, tracking bulls 10 or more miles a day in the African heat want? This little gun had all the bells and whistles one could ask for...
I took it to Africa and shot a number of Cape Buffalo with it and it worked as planned and with the drop box I opted for it held enough ammo to start WW3 !
400 gr. Woodleigh, Horneber cases,Fed 210 primers
74 grs. of WW748
61 grs. Varget All these loads chronographed 2100 plus FPS
57 grs. Norma 203B
350 Barnes X and GS Customs bullets, and 340 gr. Northforks, Horneber cases, Fed 210
61 grs. H335
56 grs. 4198 2300 to 2350 FPS
58 grs. Norma 203B
380 gr. Norhtforks
66 grs, VV-140 2170 FPS
61.5 grs. VArget 2120 FPS
Of interest is that printed matter is hard to come by and when you find it then it is European powders, but these powders are tranposable burning rates as follows:
2208=VArget, IMR-4064, IMR-4320
2207=H4198, IMR-4198, RL-7
2206= H335,BLc-2
RWS and Kynoch factory ammo clocked right at 2150 FPS
Case Oal is 2.677, Trim length is 2.666
Note: The case is quite long and if you ever intend to change it then about the only round that will clean the chamber is the 404 Jefferys and just barely so I recommend a very competent gunsmith to do such work..
Note: I think those old German smiths just stuck a reamer in those guns and when they had gone in for enough they just called it good and as a result some of the Metric chambers vary a good deal and in many cases one needs to fireform the brass from the get go, then begin his load work up..Therefore my loads are only a guide to go by..
Definatly began 10 percent below my suggested loads and work up from there..Some of the older Mausers, depending on the make and model and maker, could be a tad soft I suppose...
