My VZ-24 with a Lothar Walther 23.6" barrel is throated for 286 gr bullets plus a bit. The mauser mag likes the COAL at 3.26" with ANY bullet I happen to pick...so it doesn't matter what length the cartridge happens to be when the bullet touches the lands, if it is too long for the mag, the COAL is moot.
For the most part you need to think outside the box and forget conventional thinking because conventional thinking doesn't always work. Most reloading manuals go with SAMMI specs as far as COAL is concerned...your length may vary.
My usual method is seat touching the lands...ANY caliber...to start with and hope the COAL fits the mag...if it fits the mag at that length I shorten in 0.005" increments to find out where the best accuracy happens to be with THAT BULLET, THAT POWDER AND THAT PRIMER...you can't mix and twitch and expect the accuracy, pressure or velocity to be the same. You can go the other way around also...start short and increase the same amount.
My object is to develope an accurate load...velocity is secondary...I've found that the best accuracy comes where it happens...just like gold...you find it where it is and you have to look for it. I have guns that shoot best at loads well over published data and guns that won't make published data without blowing primers, sticking bolts, or locking up break actions.
What my rifle happens to like doesn't mean your rifle will like the same thing...nothing is free and everyone has different tastes...I barf at the smell of liver and onions and have to leave camp when the days kills liver everyone so ardently loves start cooking...so pick a bullet you want to use, two or three powders with the correct burning rate for your bullet and caliber...most larger calibers shoot the best accuracy touching the lands or into the lands...a proven primer...then go to work developing a load.
The 9.3x62 is a hunting weapon and also used on DGR game so functionality, dependability and safety are uppermost in my mind when developing a load. I work towards making the ammo do the job and NOT screw up so I keep the pressures dependent on the temperature I expect to hunt in, the COAL short enough so nothing will jam in the mag or lockup the action and check each round through the mag and chamber BEFORE starting on the hunt.
There are just a whole bunch of factors involved so you have to decide where your priorities lie then load to that end, not withstanding your level of expertise in reloading.
I shoot 270 Speers, 286 Noslers and 286 Horn PP for the most part and my shooter likes RL15 and Varget up near the top of most loading manuals limit and velocities run equal to the printed ones...I won't post any of my load information for all the obvious reasons.
Handloader mag #199 had a very good article by Finn Aagaard and my rifle matches his results so I'm very happy. It is a hard choice when deciding to pick which of my larger bores to use as they all do what they are supposed to do...sometimes it just close my eyes and grab one and "get'r'done hoss".
Good luck
