I used 139gr Hornady spire points in my 7x57 with IMR4320 powder and doing 2860fps without getting too carried away (early factory ammo for the 7mm-08 also used these same Hornady 139gr bullets). With the same powder load I found the 145gr Speers also an excellent killer. Used both these loads on good sized red deer and chamois and had excellent results. Some 175gr WW factory loads I tried did not kill anywhere near as instant as did the lighter faster slugs with which I had no problems getting good penetration and fast kill.

I never did try out any heavier bullets in 7x57 reloads but used a tonne of 160gr Sierra SBT in my 7x61 at 3000fps and this load could not be faulted on reds, chamois, tahr, whitetails and fallow at any range.

As I have oft quoted, the incorrigible Jack O'Connor's wife used a 7x57 with 160 Sierra SBT doing 2700fps to take 17 head of plains game in Africa with 19 cartridges. Apparently she heart shot a kudu and then used two more shots to drop it to prevent having to follow it too far. Everything else were one shot kills. That's a pretty good testimony to the old timer cartridge and the Sierra bullet. I don't use any other brand of bullet in any of my present and past guns other than my 404 which of course Sierra doesn't make bullets for.
Another example was my hunting friend using his 7x57 on Aussie buffalo with some loads I prepared for him using 160gr Nosler Partitions.