458 win mag Winchester Super X 510 gr ammo

[Mountaineer]

Does anyone have experience with this ammo? Thanks!

 

[Forrest Halley]

The 510 grain projectiles haven't been loaded in a long while. There may be a case for pulling bullets and repowdering the cases with something modern like 4895 or 748. Just my two cents to avoid clumping powder potential and achieve improved performance.

 

[Macduff]

Does anyone have experience with this ammo? Thanks!

Did you happen to win some at an auction last week?

If so, we might have bid against each other.

There were several lots of it that came through one auction I was watching. I don't remember which one though.

 

[Mountaineer]

I did not. A local gunsmith had some. Have you hunted with them before?

 

[Mountaineer]

How much did they sell for at the auction?

 

[Macduff]

There were several lots but in the $85-95 per box range.

https://hibid.com/catalog/481161/stunning-private-collection-firearms--silver-and-gold-auction

 

[Hunter-Habib]

Yes. I used them extensively during the 1970s. I never thought too highly of them.

1) The bullets themselves were far too poorly constructed for use on Cape buffalo or hippopotamus or rhinoceros. They were fine for thin skinned game such as lions or leopards, but the velocity was far too low to reliably stop the charge of an adrenaline fueled great cat (more on this in point #2). The great cats having a highly developed central nervous system, are always extremely susceptible to hydrostatic shock. And bullets travelling at high enough velocities are the key to accomplishing that.

2) These cartridges contained compressed charges of ball propellant. Fresh ammunition was capable of achieving 2087FPS out of the 25" barrel of a pre-1964 Winchester Model 70 (even though the advertised velocity was 2130FPS). But due to the compressed nature of the ball propellant load, shelf life was incredibly short (esp. In the heat of Africa/Asia/Australia). Powder clumping of the ball propellant was inevitable, which would lead to partial ignition and erratic velocities.

This is a photograph I took of factory loaded Winchester Super Speed .458 Magnum ammunition after opening a few of the cartridges. Observe the grotesque degree of powder clumping.

Later in the mid 1970s, Winchester (in a misguided attempt to improve cartridge shelf life) reduced the powder charge of their .458 Winchester Magnum factory loaded ammunition to an advertised 2040FPS. Actual velocities were in the ambit of 1950FPS. And this caused Winchester's factory loaded .458 Magnum ammunition to become completely inadequate for dangerous game hunting altogether.

By 1997, Winchester had discontinued their .458 Magnum ammunition altogether.