Karl-

Thanks for your response.
What you've noted is very similar to what a friend and I came to over fairly thorough research into this proposed project.

I'd briefly thought of flirting with the 40k range, but down in the sub 30k arena I'm designing with a much greater margin of safety. With a wee bit of jump into modern barrel steel I'm feeling good about muzzle velocities in the 1700fps range.
I see this thing as a micro express rifle with a tidy little express sight zeroed at 75 yards.
Should be hell on jackrabbits inside 100 yards and a lot of fun to shoot.

--Tinker