I've been knocking this around alot lately too and scratching my head over the different cases.
It's a quest for a 'little brother' to my .25-06 that has been lengthy.
Here's some more specifics on the jobs I want it to perform:
Case: Ideally I'd like a rimless case that uses LARGE RIFLE primers. Overall dimensions don't really matter after that, expect...
Capabilities: Here's where the current cartridges seem to fall down for me. I want to be able to use bullets from 60-65 gr up to 90-100 grain TOPS. I'd settle for a 65-85gr range. I want to keep velocities down under 2,000 FPS on the slow end, as slow as possible actually. I'm basically looking for a .22 on steroids by being in .257". I would like a squirrel killing capability at the low end. Yet, I'd like the heaviest bullet to have the capability to take a shot at a deer if necessary out to about 100 yards.
From all my researching, the .25-20 is just too small for the top end. It does well for the bottom end. The .250Savage/3000 and .25Remington is too big for the bottom end and gets too close to my .25-06 for the bigger stuff.
I can't download the .25-06 enough due to the case size. I can't load up a .25-20 enough either. The .257TCU (.223/.222RM case family) seems to be as close as I can get, BUT they all use SMALL RIFLE primers. If I could get them with Large Rifle primer pockets, I think it would be a go!
![Wink ;)](https://www.gboreloaded.com/forums/Smileys/default/wink.gif)