When Winchester released the .458 Winchester Magnum in 1956 , factory loaded ammunition had an advertised velocity of 2130 FPS (a chronograph test in an HP Laboratory in 1961 documents the actual velocity as being 2087 FPS, out of the 25 inch barrel of a pre '64 Winchester Model 70) . Loads were a 510 gr soft nose and 500 gr steel jacketed round nose FMJ . When Remington started manufacturing .458 Winchester Magnum factory loaded ammunition in 1961 , advertised velocity was also 2130 fps . Offerings were a 510 gr soft nose and a 500 gr steel jacketed round nose FMJ (with a thinner steel jacket than those offered by Winchester) .
Now , when fresh ammunition was used , These velocities were indeed accomplished (or at least, close enough to get the desired effect) . The problems arose with ammunition, which was a little old ( Like a year or two ) . The Compressed olin powders led to clumps . This resulted in erratic velocities ( Often lower than 1900 FPS ) . Bullets would also slowly get pushed out of cartridge cases , as well . This caused feeding problems in short actioned rifles ( FN Browning , Interarms Whitworth Express , etc ) .
In '73 , Winchester and Remington BOTH lowered the advertised velocity to 2120 FPS , in an attempt to increase shelf life . However , the problems were still there .
In '78 , Winchester and Remington Both lowered the advertised velocity to 2040 FPS , in another attempt to increase shelf life . Shelf life was improved , but now the Winchester and Remington factory ammunition was inadequate for frontal brain shots on big bull elephants ( and Matriarch cow elephants ) , and frontal heart shots on Cape Buffalo . Also was inadequate for Rhino and Hippo on land .
The Elephant cullers working for the game departments in the National Parks ( Like Clem Coetzee and Mike LaGrange ) in Zimbabwe ( Then , Rhodesia ) and the cullers working for Tseste Fly control and Cape Buffalo eradication culls found this out the hard way ( From the 1970s to the 1990s ) .
Art Alphin ( Owner of A Square ) decided to help the game departments , by providing them with specially loaded .458 Winchester Magnum ammunition . These were Remington Peters cartridge cases , loaded with 500 gr Hornady round nosed steel jacketed FMJ solids . They were loaded to early Winchester's original advertised velocities of 2130 FPS .
These were performing satisfactorily , but the original problems found in the pre '78 Winchester and Remington ammunition began to resurface ( Short shelf life ) .
In '87 A Square ditched the 500 gr Hornady round nosed steel jacketed FMJ solids , and began to load their ammunition with 465 gr monolithic solids . This accomplished a velocity of 2200 FPS . But again , if the ammunition sat around for a couple of years in a shelf or a closet , then velocities became erratic and the bullets started slowly getting pushed out of cases . A Square monolithics also caused excessive strain on rifle barrels ( Rifle barrels were getting shot out , only after less than 500 firings ) .
In 1992 , Federal started offering their Trophy Bonded Bear Claw and Trophy Bonded Sledge Hammer Solids in .458 Winchester Magnum . These used a 500 gr bonded soft nose or a 500 gr bonded steel jacketed round nosed FMJ solid . However , these loads accomplished little above 2000 FPS , and frequently below 1950 FPS . Also , when Jack Carter stopped being involved with Trophy Bonded Bullets , the bullet construction notoriously deteriorated .
After 1995 , Hornady started offered factory loaded ammunition for the .458 Winchester Magnum . This was called their " Heavy Magnum " line and were loaded with round nosed steel jacketed FMJ 500 he solids and 510 gr soft nose . Advertised velocity was 2230 FPS . How ever , shelf life was only 6 months . This high pressure ammo was also causing extraction problems on bolt action rifles in humid climates ( Like Zambezi Valley ) .
In 1996 , Remington stopped offering their 500 gr FMJ loading , altogether . The discontinued the offering , and only offered a 450 gr Swift A Frame loading , for a few more years . Then , they discontinued their .458 Winchester Magnum ammo line , altogether .
Finally around 2006 , Hornady fixed the problem by releasing their DGS and DGX line . These were a 500 gr Flat Nose bonded steel jacketed FMJ solid and a 500 gr soft nose bonded bullet . Advertised velocity is 2140 FPS . The shelf life problems have ( largely ) been taken care of . Because Hornady uses a special fine grain cool burning powder . However , you occasionally still get reports of fluctuations in velocity . Hornady DGS solids also have a small propensity to distort on Frontal brain shots or shoulder shots on big bull elephants and shoulder shots on Cape Buffalo .
The best solution nowadays is to hand load and ditch the 500 gr bullet , and use a 480 gr bullet ( As sold by Hornady and formerly Woodleigh ) . These improve case capacity enough to solve the shelf life problems , permanently .
In 2009 , Winchester listed two different loads for their .458 Winchester Magnum factory loaded ammo : - A 500 gr Nosler Partition Soft nose , which was advertised as only accomplishing 2010 FPS - A 500 gr Nosler monolithic solid , which was only advertised as accomplishing 2010 FPS .
Needless to say , neither offering was a success. In 2010 , Winchester dropped their .458 Winchester Magnum ammo line , altogether .
Avoid monolithic solids in the .458 Winchester Magnum. Monolithic solids need to be longer than a conventional FMJ solid in the same weight ( In layman's terms : A 500Gr monolithic solid will need to be longer , than a 500Gr FMJ ) . Thus , increased powder space gets compromised . In a caliber like the .458 Winchester Magnum ( Which is already well known for case capacity issues ) , this becomes a huge problem . If you gotta use monolithic solids in the .458 Winchester Magnum, then stick to 450 - 465Gr monolithic solids . Nothing heavier .
I hope this helps. Last edited: May 19, 2022
Ron aka "Rip" for Riflecrank Internationale Permanente NRA Life Benefactor and Beneficiary .458 Winchester Magnum, Magnanimous in Victory THE WALKING DEAD does so remind me of Democrap voters. Donkeypox.
