The Scirroco is a bonded/premium bullet and will give the same performance as a partition, a frame etc. or maybe better and will penetrate deep. Go for it in the 30-06.
Yes, it is a good bullet by my experience. The only witness and experience I have with the Scirocco is on 900-1000 lb elk. That bullet in 180 gr 30 cal will do fine on nilgai and similar-sized game.
Swift, in the Scirocco design, avoided a huge design flaw by some manufacturers from the beginning. Some manufacturers were too eager to enter the bonded bullet game and "get in on the marketing hype and action".
The Remington Ultra Bonded was one of the worst!
Remington simply bonded a soft lead core to a very thin jacket which proved little better than one of their early, cheap,
frangible cup and core, soft point bullets. Swift purposefully designed the Scirocco with a much, much! thicker jacket thus solving that shortcoming before even marketing the Scirocco. Shoot a 600 lb nilgai in the right place with a 180 gr 30 cal Scirocco, as with any big game animal and no issue. Get sloppy and all bets are off, as with any big game animal.
Study the cross sections of various bullets to better understand the hows and whys. The internet is a great research tool if used properly
Scirocco on left and A-Frame on right. Note the thick, tapered jacket on the Scirocco and the solid supporting base.
The next heading or thread of course will be all about how good a 6.5 (whatever) is for 1800 lb eland