You should have no problem using the jacketed starting load listed in your manual & then adjust your load from there.

If you drop under the minimum load you should keep an eye on your case capacity. Too much space and the ammo starts to get erratic (position sensitive).

You should go over and look around on the castboolit.com website. There are several members there that are from New Zealand and their good with cast bullets/rifle data (jeffinNZ is a moderator and has a website
Beaver Grease).

Do a search for 4064 & varget, you'll find pages and pages of data/loads on the castboolit.com website.

Been working on 10-shot groups @ 100yds that will do moa. 2400 in a 308w, the load needs a little tweeking ( 1 3/8" outside to outside)


good luck