So, Hornady markets a Superformance factory load for the 9.3x62 using a 286gr SP at 2,360fps, which is a standard velocity for this round, but only offers it outside the US. From what I can see (although at least two US sources carry it including Buds).

I presume that the Hodgden Superformance powder is mostly equal to the canister grade the Hornady is using, so I'd like to know if anyone has bought a box and pulled a bullet to get a charge weight.

I'm thinking it might be a good starting charge for reload development as it's likely loaded light for use in older European guns, and not modern rifles like the CZ.

The 9.3 x 62 was invented in 1905 for Mauser conversions to existing rifles in the German African colonies. How weak could they be? Mausers have a stellar reputation for toughness, after all.

Maybe not. I had a conversation with a rep from Hodgson over the phone about using their canister a performance powder in 270 for which they dont offer load data. IIRC he stated that the blend they sell to the public is one of maybe 40 something blends they have worked up for various purposes. They said that these powders are tailored for specific cartridges and have very tight burn rate profiles. In other words the one and only blend of a performance they offer commercially should only be used in cartridges that they list data for. We talked about working up loads for other powders were no data is available and he said that a performance is like no other single or double base powder. It has a lot to do with the nitroglycerin content and the coatings they put on the powder to modify the burn rate. It is a tailor made hugh performance powder.

Another option for the 9.3 however may be vhitavouri n550. It is a high energy powder that will help you squeeze out top performance in the 9.3  it is expensive at $45 or so a pound and I havent tried it fearing I'd like it too much and would feel compelled to break the bank to shoot it as much as I do. I shoot hundreds of rounds of 9.3 a year. To be honest I really love varget in my gun. It's super clean and I'm able to get single digit standard deviations in velocity. I can also safely push a 270 grain spear hot cor at 2440 fps while getting sub moa 5 shot groups. There is absolutely no reason for this gun to need to shoot this well but it does.

Enjoy and stay safe reloading.