Bakes I have a friend who has shot over 100 sambar but only 5 with the 45/70 says he likes the 45/70 as a sambar rifle. Furthest shot was at 120yds the first shot went through both shoulders and stopped under the skin, followed up by 2 further shots to stop it. Winchester factory ammo.
He has a strong dislike for the 270win says it is responsible for a lot of lost sambar.
other cartridges he has used
35 Whelan
308 win
300 win
375 H&H
30-06 (he still uses this one and the 45/70)
Plus his bow

I know another bloke who swears by the 270 as a sambar rifle calls it the "beltless magnum" although he has shot less than 30.

An allful lot have been shot with the 303.
The 30-06 woody was very popular with doggers until the bastards took them.
Have been out a couple of times with the 416 but yet to see one, in years past have also gone hunting with 270 and 308 but no shots fired.