Well, o'google'wonderful was able to back track the image upload to this site: https://www.all4shooters.com/en/Shooting/ammunition/375-Holland-Holland-ammunition-hunting/?p=1
says its a 416 rigby soft point.
And HOLY crap are they expensive!!!
Yes, so I'm trying to talk them into nickel 30.06 dummies as a substitute.If you can even find nickel brass for the .416 Rigby, you are still looking at $2+ per case plus the cost of the bullet. You would still save some by reloading but not as much since you wouldn't be reusing the case.
Why on earth would someone need that many nickle-plated dummy rounds? Just curious.