Bit late chiming in. Sambar are a bit more tenacious than Red or Elk. Yes I have seen a stag drop to the shot from a 30-30. I have also helped look for more than one Stag hit solidly. One with a 220grain projectile from a 30-06 from 20 mts. Plenty of rib bone and bright trothy blood. 20 blokes could not find the Stag. back 2 days later with dogs and the Stag was still not found. if he died he moved a long ways before he did. Same helped look for one hit twice with a 375 H&H bright blood and both shooters claimed solid chest hits.

I broke both front shoulders of a Stag with the 35Sambar. He porpised off his hind legs for 150 mts before stoping. They, when their blood is up, are a very tenacious animal and Reds do not compare. Yet plenty have been taken with a 243 before the calibre restrictions in Vic. Don't hear about those lost.

I would not hesitate to use a 7X57 with heavy well constructed bullets.