.458 Winchester Magnum

Technical Specifications

 

Country of Origin United States
Diameter – Bore .450” (11,43mm)
Diameter – Groove .458” (11,63mm)
Introduced 1956
Pressure – Max Average 62,000 psi (428 MPa)
Regulators CIP / SAAMI
Groove Details 6 x .1500” (3,81mm)
Shellholder – RCBS 4
Twist – Proof Barrel 1:14” (3560mm)
* Read all about this cartridge in the book African Dangerous Game Cartridges by Pierre van der Walt
Cartridge Essentials

 

Action Size Recommended Standard length with magnum bolt face
Barrel Life 7,000 – 7,500 rounds
Case – Body Taper 0.8°
Case – Neck Length .458” (11,63mm) = 100.0%
Case – Trim Length 2.492” (63,30mm)
Parent Case .375 H&H Magnum shortened
Relative Capacity 95.0 gr water (6,168cc)
Shoulder Angle 0°00’00”
Typical Factory Load Guidelines for – Solids
Brand Name Weight Bullet Description Velocity Fps Energy Ft/Lb Trauma Potential 0% Expansion
Federal 500-gr Speer AGS Solid 2,090 fps 4,851 ft/lb 83.4
Hornady 500-gr Hornady FMJ RN 2,260 fps 5,672 ft/lb 97.5
Norma 500-gr Barnes Solid 2,067 fps 4,475 ft/lb 81.6
Typical Factory Load Guidelines for Africa – Expanders
Brand Name Bullet Weight Bullet Description Velocity Fps Energy Ft/Lb Trauma Potential 100% Expansion
Federal 500-gr Speer Trophy Bonded 2,090 fps 4,851 ft/lb 41.7
Hornady 500-gr Hornady RN Interbond 2,260 fps 5,672 ft/lb 48.8
Norma 500-gr Swift A-Frame 2,116 fps 4,972 ft/lb 42.7
Optimum Game Bullet Optimum Bands (400-gr averaged)
Band Velocity Parameters Start End
Green-Band ( ≤ 2,600 fps – ≥ 2,200 fps) ± 0 yds ± 0 yds
Amber-Band ( ≤ 2,200 fps – ≥ 2,000 fps) ± 0 yds ± 67 yds
Bullet Recommendations for Africa
All species Solids. On pachyderms use flat nose monometal solids
African Game Weight Recommendation
≤ 13,000-lb ( ≤ 6000-kg)
Most Suitable African Species (assuming legality)
Pachyderms      Buffalo, elephant, (body shots), rhino
* Read all about these animals in the book Game Animals of the World by Chris & Tilde Stuart
Optics Guidelines
Eye Relief Critical ≥ 4.0″
Exit Pupil ≤ 5mm
Magnification: Amber-Band ≥ 1x
Objective Lens ≥ 20mm – ≤ 24 mm
Parallax Adjustability No
Reticules Bold posts. German #1, #2, #4, #9, #56
Consider illuminated dots
Consider reflex
Handloading Guidelines
Load Development 1.0 grain increments
Primer Any Large Rifle Magnum
Propellant Range Medium-burning rifle: ≥ IMR-8208 – ≤ Hodgdon H-4895
Tips Use normal taper crimp. Can augment with Lee factory crimp
Use foam filler to improve combustion consistency
Full length resize hunting loads
Check feeding before
* Read all about this cartridge in the book African Dangerous Game Cartridges by Pierre van der Walt