Try Greg Simons at Wildlife Systems. He hunts all over the place and has some excellent Nilgai ranches in STX to hunt. I killed one on the King Ranch several years ago and the smallest gun they would let me use on that ranch was a 338 WM. They prefer a 375 or larger. Mine dropped like a rock at 225 yds with 210 gr Nosler partitions, but I had a perfect shot and the guide said he had never seen one go straight down. Several others that week had some serious tracking with the thick brush, but I've always believed shot placement was king. Not sure what Greg suggests for his hunts, but a 270/3006 have been bringing down big critters for years.
They are excellent table fair! Good luck!
