458 Win Mag reloading

[Frogman]

Hi all. I need some help please. I am a Professional hunter and have been given some bullets for my 458 win mag over the years but cannot source reloading data for them so i have joined this groups in the search of some help.

I only have South African Somchem Powder (S321) available and cannot get the correct info from their website or booklet.

I need min and max loads for the following if someone can help me

1. 450gr Swift A Frame.

2. 450gr woodleigh hydro solids.

3. I have also been given a box of 465gr round nose solids. This unique thing with these are that the diameter is .457.

Thank you in advance

 

[Markopolo50]

Welcome. I have found some information for you. Your powder is similar to IMR 4895 and Hodgdon 4895 and close to Norma 401, 402.

First here is a powder burn rate chart listing your Somchem Powder, S321
http://gsgroup.co.za/burnrates.html

Second is reloading data from Norma's website showing loads for the 450gr Swift and loads for a 480gr Woodleigh. Not the same weight as your 450 Woodleigh but use for reference

https://www.norma-ammunition.com/us/Ammunition-Academy/Reloading-Data/458-Winchester-Magnum/

What brand are the 465gr solids? .457" is just .001 undersize. I don't have any 458's to measure so I can't advise.


Good luck

 

[AZDAVE]

Sat down and ran your request through quick load. As per normal reloading practices start 10% below and work your way up to find what is safe in your rifle.
458 WM with a 24in barrel
450 Aframe 75gr of S321, 100% case fill, 2309 FPS velocity, 61896 barrel pressure
450 woodleigh 73gr of S321 101% case fill, 2277 FPS velocity, 59541 barrel pressure

 

[Shootist43]

Pierre van der Walt's African Dangerous Game Cartridges shows 68.4 Gr. of Somchem S-321 as a minimum and 76.0 Grs as a maximum. Velocity expected is 2211 FPS from a 24" barrel pushing a 450 Gr. bullet. These are published data, others may have data that has been verified by chronograph

 

[MMAL]

Not sure what brand of round nose you have but swift a frames .458 caliber bullets are listed at .457 diameter. I questioned that as well.