Or a 6.5 wildcat off the 9.3x74R by any other name?

It's just another over bored no where to go wildcat cartridge.

I should clarify me comment. I was playing around with computer models of a 6.5mm wildcat using the 9.3 x 74R. It just seems to me there is not much that cartridge would do that isn’t already covered by other cartridges.

I have no direct knowledge -

This should be pretty close to a 6.5-06 Ackley, the main draw would be the rim for single shot rifles. Is this why you're interested? Graybeard Outdoors is pretty much the go to resource for Handi Rifles.

David White has set up a niche business as a Handi Rifle guru, and as such has a "problematic" reputation (hidden charges for barrel stubbing / not straightforward).

The problem for Handi Rifles is there is no direct donor chambering in .264 (6.5). So it would require a barrel stub or reboring, maybe $600. So it would purely be a labour of love.

Cheers and Good Luck.

Yeah, for a single shot. I ordered a book about building a falling-block action. The builder made his in .225 Winchester. I'm wondering about a slightly larger action that can fire something that would be a ballistic clone of the 6.5 Gibbs I had years ago...so a rimmed .30-'06 class case. The 9.3x74R is bigger. It's .264 WinMag class (I didn't know the case capacity when I posted the OP), but it could be cut down.

Of course, another, smaller case could be a starting point. My load was 57.5 grains. The 7x65R holds 68gr of water. That one might be a good starting point.

I keep reading that these rimmed rounds use light loads, because they are made for break-open rifles. I've been wondering if falling blocks also need light loads. (I've never owned anything but bolt-action rifles). Then I remembered that the 120mm main gun in the Abrams tank is a falling block.

https://www.youtube.com/watch?v=RNTDyJmKCnQ

A 9,3x74R case holds 83grains of H2O subtract maybe 5 grains for new neck and 78 grains of H2O is the result.
A 264 is 82gr.

It's going to be a barrel burner for sure!
Less than 2000 shots and you're off to get another barrel fit.

Oh yeah, brain fart, what you want already exists, sorta.

6.5x68r

Falling blocks probably would work, a donor Ruger1 or Miroku made hi wall 1885 or B78, too.

Maybe there should be a pinned thread called "Has my idea already been done?" I do like wildcats, but many of them are people reinventing the wheel.