Well whadya think? 23 or 20? 25 I feel is definitely too long. I have a 308 with 20 inch and really like it. However, this will be my bigger than .375 H&H gun and I want it to perform as intended.

Will I be giving up any useable velocity? Will I still be able to reach 2300 with 400 gr bullets? Even though I'll probably be happy with 2150.

I guess the biggest question is for mauser type A rifles in this caliber......What was the standard barrel length?

Andy

Type A Oberndorfs had 24" (23.62") barrels which is the length I would stay with.

2300 fps with a 400gr in a 10.75x68 will be pushing it and what for. The 404J made its considerable name with a 400gr around 2125fps to 2250fps and the modern loadings for this cartridge were just over 2300fps.

The 10.75x68 was a good general purpose big game cartridge with 347gr bullets but like many, suffered from some poorly constructed ones. Today with modern 350 grainers this cartridge should be fine performing at it's design level.

24" sporter weight ... case capacity isnt great enough to give more than around 2150fps with 400gr.
Cheers...
Con

2150 is easy
23" barrel .. remember, Andy, your LOP is going to be a tad longer