I'm fairly new at reloading, having done only straight-wall pistol cartridges with mild loads on a single-stage press so far. I bought the press so I could afford to shoot my .44 Magnum, and I figured it would also work well for loading hunting and precision rifle ammo. This past weekend, I needed to go tinker with the roll crimp for my .38 Special recipe, and I figured what the heck, now that I've fired a few boxes of the Prvi factory ammo, I'll use the empty cases and dial in an initial batch of 9.3x62mm as well.
One thing I've discovered about reloading is that the ammo drought has extended to reloading components as well. I've got cases and projectiles, and was able to scrounge up 1000 WLRM primers, but powder is hard to find, especially locally. That's important, because when working up a load, I don't want to buy 8 lbs of a powder I might not end up using, and the combined hazmat and shipping fees are more than most 1lbs cans of powder cost. At those prices, I might as well just buy factory ammo. So after striking out on more common powders like Varget and RL15, and reading some various forum posts about people using it for the 9.3, I was rather happy when I found a single pound of Ramshot Big Game in a local store and forked over my money.
Now, as I mentioned, I'm new at reloading, and I don't consider myself anywhere near the level of experience to start going off into the weeds on load recipes. As I gain more experience, I might start doing some experimentation, but for now I stick to the book religiously, including component selection, measurements, etc. So imagine my surprise when I can't find any published data that uses Big Game in the 9.3 (Hornady lists TAC, and Barnes doesn't list any Ramshot powders for this cartridge), and only a few mentions of using Big Game specifically with Prvi cases and bullets (note: I don't plan to take Prvi bullets to Africa, but I do intend to use them for familiarization shooting, learning the initial ins and outs of reloading bottleneck rifle cartridges, and likely some whitetail hunting without breaking the bank on premium bullets. For the actual safari, I will be loading up the tried-and-true Barnes TTSX and either Barnes or Hornady solids.) My 'economy load' for practice and familiarization won't pan out if I can't find load data for it. So, off to the internet I go. And lo and behold, I found www.realguns.com had some data for Big Game with Prvi bullets. Awesome.
And so after I set up the RCBS neck sizing die and resize/measure the first sacrificial case, it's time to dial in the seating die. I'm hopeful that I can get everything zeroed in and start loading my initial batch. And before I seat a round, I take a look at the printout of the load data and I notice a little asterisk next to the COL data for the Prvi bullets. The data for this particular load has a COL of 3.305", 0.014" longer than the maximum COL in every factory book I've read (3.291"), and 0.030" longer than the COL of my factory Prvi ammo (3.275"). Spider sense... tingling. At this point, I put the dies away and go back to Google. Eventually I found someone using that particular recipe in a Ruger African with no issues, though he did back down the rather heavy powder charge and used non-magnum WLR primers. So, I emailed the Ramshot people to ask if they had any recipes for Big Game with Prvi bullets, but they don't.
So, for any of you more experienced reloaders out there, what would you suggest? Pick the data for a similar bullet, seat to normal COL, and start with a lower charge and work up? Keep looking for data for the exact components that I have?