Thanks to all for your thoughts and especially Laurie for his detailed answers.
These are my choices as I see them and feel free to correct me if I'm wrong about anything.
Pretty much all the cartridges mentioned, from .223 to .308, can, in good hands, with the right ammo, in a decent rifle achieve acceptable accuracy (sub MOA) up to at least 600yds with reduced recoil.
I'm dividing them into 4 groups : 5.5mm, 6mm, 6.5mm, 7.5mm (I don't think we've mentioned 7mm)
5.5mm i.e .223
Cheapest to run with good barrel life. Least recoil of all. Available in 9" twist varmint barrel for around £500. More affected by wind drift than larger calibres so potentially more challenging. (We like a challenge).
Something like this
6mm ie 6mmBR and. 243
6mmBR doesn't seem to be available in budget but sounds excellent.
.243 - ticks all the boxes. Question mark over barrel life but given I'll likely only shoot 200-300 rounds per year may not be an issue anytime soon especially if I shoot light loads.
Pretty
Another stainless
These are both local to me and the first one is my favourite.
6.5mm - 6.5 Creedmoor, .260, 6.5x55
Nothing significant to choose between these. Does everything I need. 6.5x55 would be difficult to change to a different calibre later due to the long action and along with. 260 are hard to find in budget.
Not stainless but new
Above also available in 6.5x55.
7mm ???
7.5mm ie .308
Soft loads/muzzle brake/moderator to manage recoil. Probably the widest choice of used and new within budget.
Why choose. 308 when I could have 6.5 creedmoor?
Just an example
Summary
Keep it simple = .223
Low cost gun = .243
Just do it = 6.5 Creedmoor
Thanks again for everyone's help.
