Having grown up shooting a 7x57, I've always had a soft spot for them. I've listed a few assumptions below from some research I have done on the calibre recently - please correct where necessary!
1) Factory ammo tends to be loaded quite conservatively - this is due to the age of most 7x57 actions.
2) Velocity and Energy levels for the same bullets seem to be on par with 7mm-08 (Factory ammo).
3) 7x57 has greater case capacity than the 7mm08.
Therefore, if you home loaded, and had a new 7x57, presumably you could squeeze a bit more out of it safely?
Do the reloading manuals also give conservative powder amounts for the 7x57, or do some take newer actions into consideration?
I'm thinking about a new rifle, and it would seem to make more sense to go for a 7mm08, however if I could find a new 7x57 (e.g. Blaser R93) perhaps I could get more out of it, and it would be nice to revert to the calibre.
Thanks, and I look forward to your comments.