I have the rimmed version 7x65R - lovely calibre. And very versitile. You can use a 173gn bullet that is more than capable for thumping big large animals. I have shot 100kg Boar with mine without any fuss or bother.
Just read the article you referenced Heym, very interesting indeed thank you.
With a streamlined 140 to 156 grain bullet it has a high ballistic coefficient and enough case capacity to push it fast and flat. I have some RWS loaded with their non-toxic HIT Bullet at 2,900 fps. Normal inch high at 100 zero, I am hitting a 5" gong on the range at 230 metres in the centre with cross hairs in the centre.
Yet you can also load a 140 gn at a mild 2600 fps and good for Roe etc. - I have used such a load - a 139gn Hornady softpoint over IMR 4831 to take lost of Roe from 20 yards out to 200. They have all fallen over without much fuss. And also taken lots of foxes with the same load. And out of a 26" barrel its pretty quiet.
I have taken one Chamois, but not with my rifle, but no reason why it should n't work very well.
I am very surprised that the 7x64 / 65r are not more popular in the UK. They don't have the high pressure crack of the 270, and don't have the recoil of the 30-06 and mostly very smooth shooting. Yes with big bullets and fast loads they have a bit of recoil, but in my combination gun I reckon the 16 bore barrel probably has more. And yet they are very well balanced and a god all rounder. Any better than the 7x57 - possibly - but not at the smaller bullet weights, albeit a lot of 7x57 ammo is not loaded to its full potential. But it does have quite more authority when you getting to the heavier bullet weights.
Ammo is available in the UK, and increasingly available. But it is not everywhere, and you do need to think ahead a wee bit. It helps if you have a reasonable quantity on your ticket so you can buy 100 rounds at a time. RWS is good ammo, but expensive. Geko is just as good, but much much more affordable, and look down at Sellier & Bellot and Prvi as they are very affordable and work well. Beauty of the 7x64 is you don't need expensive bullets to work well. And its straightforward to reload.
Here is a video of the 7x65R which I posted elsewhere:
and this is well worth a read