Out of idle curiosity I have had a trawl on line of the 25 high B.C. wildcat speculation as @
caberslash mentioned.
Certainly interesting
But @
Tentman you are already running 6mm and 6.5mm bolt guns which should do exactly the same task
Why not go back to your roots Foster and do a 25 cal single shot ?
This is one time I would advocate for the Ruger no1 and an old fashioned 25-06 with a nice new fast twist SS barrel.
With a modern strong single shot action cartridge over all length will never be an issue.
A 25-06 chamber reamer with a long throat should be around ( I will ask my contacts ).
Brass and dies will never be an issue
Just find a donor Ruger no1.
Then you don't have to reinvent the wheel