After quickly reading my copy of the book written by Mr. La Grange , l was able to find what you are looking for
@Hoss Delgado . Here is the information :
The issued rifles used by the Department of National Parks and Wild Life Management for culling the African elephants were as follows-
.458 Winchester magnum Mauser bolt rifles made by Fabrique Nationale , all of which had to be " re head spaced and re blued "
.375 Holland & Holland magnum calibre pre 64 Winchester Model 70 bolt rifles , all of which had to be " re head spaced and re blued "
Regarding Mr. La Grange's personal rifles , he only makes mention of a pre 64 Winchester Model 70 chambered in .375 Holland & Holland magnum with a " bull barrel " .
Mr. La Grange deems the .375 Holland & Holland magnum calibre , as suitable for side brain shots on elephants , but not frontal brain shots .
There is a chart in the last few pages which lists all of the calibres used for the elephant culling .
The .458 Winchester magnum calibre was used the most , using 500 grain solid metal covered Hornady bullets , loaded by a company named A Square .
After that , the .375 Holland & Holland magnum calibre was used the 2nd most , using 300 grain Hornady solid metal covered bullets , also loaded by the company named A Square .
Nothing else is mentioned .
The charts mention that the following calibres were tried on elephants , but were not fired in sufficient quantities for any real culling :
1 dozen .458 Winchester magnum calibre monolithic solid bullets were also used , made by the company , Hornady ( in 470 grain weight )
6 cartridges of .416 Rigby were fired . These were 410 grain solid metal covered bullets made by the company , Hornady
5 cartridges of .470 Nitro Express were fired. These were 500 grain solid metal covered bullets made by a company named Bell .
The numbers of cartridges expended in these calibres are a good indication that these calibres were barely used at all for the culling conducted by Mr. La Grange .
I have only listed whatever he actually mentions that he used , not what he recommends .
I am afraid that l cannot give you anymore information , Hoss Delgado . The author's thoughts are very scattered and you need to read the book yourself to get a more clear picture .
However , this is a very good book . I purchased it , mainly because l was ( and still am ) fascinated by elephant shooting , since that is the 1 brute in India which l never got to hunt.
He ( like any sensible shikaree of thick skinned game ) makes no mention of using any .30-06 Springfield calibre fire arms for dispatching elephants .
All the best .