The Ultimate 458 SABI

The 458 Win Mag has always been a good backup round, but with the round nose bullet at a velocity of around 2000ft/sec, it was hardly ever used as a general purpose round. Why Winchester never improved the 458 is unknown but crazy, Jack Lott was the one that took a straightened 375 H+H case and loaded the 458 Bullet. 
We invested in 458 Lott chamber reamers and converted many rifles to the caliber which is a very successful conversion and such a rifle can fire both 458 Win and 458 Lott rounds. Even with a velocity of 2250 ft/sec we found that every Lott owner still tried to get the maximum velocity from the Lott case.
As our very successful 338 SABI and 270 SABI was only a combination of the better qualities of other rounds, we decided to look at the possibility of getting more out of the 500 grain 458 bullet. With the cost of magnum Mauser actions out of reach for many people we had to develop a round that could be used in the standard K 98 Mauser action so the basic 500 Jeffery case was chosen. The main problem was to get 500 cylinder cases and after searching and with the help from others we found cylinder cases much cheaper than the brands we used in the past.
We shortened the case to 68 mm and allowed for a 10 mm long case neck and more taper to the shoulder than the 500 Jeffery. Despite the shorter and more tapered case it could still hold 110 grain of powder, which would make a very powerful round. The testing was very interesting as it is with all unknown rounds. It takes a lot of different loads and also powders before the final loads are accepted.
S 335 showed pressure before the velocities we wanted were reached. We tried S 341 but it showed no consistency. The case full of S 365 did not reach the required velocity of 2500 ft/sec. The only answer was a duplex load and soon we found the velocity of 2550 ft/sec. for the 500 grain bullet. We were pleased because we never intended to shoot at a velocity higher than 2400 ft/sec. for the 500 grain bullet.
We then loaded Woodley's 550 grain bullets to a velocity 2300 ft/sec. which was all we tried to achieve as that would be about the best penetrating round available.
A standard K 98 action rifle can carry two in the magazine and one in the chamber. When using the wider, deeper magazine box which we manufacture for the 500 Jeffery, it will carry 3 down and one chambered. The standard ZKK CZ action needs very little work and takes three down and one in the chamber.
The loading and performance data are as follows:
    MV ME 50M  75M 100 M  125M  150M
500 gr SP 2300 5872 +0.64 +0.63 0.0 -1.29 -3.29
500 gr FMJ  2400 6394 +0.54 +0.55 0.0 -1.16  -2.96
550 gr FMJ 2300  6459 +0.63 +0.62 0.0 -1.25  -3.22


      Ballistic Co-efficient    Sectional Density
500 grain Woodley .272 .341
550 grain Woodley  .300 .375
With sectional density of .375 of the 550 grain bullet and ME of 6185 the 458 SABI will be the best penetrating round available in a standard action rifle.
The comparable penetration ability according to our formula is as follows.
375 H+H    300 grain bullet @ 50meter 812
458 Winchester  500 grain bullet @ 50 meter 1426
458 Lott 500 grain bullet @ 50 meter 1680 
458 SABI  500 grain bullet @ 50 meter  1972
458 SABI 550 grain bullet @ 50 meter 2057
500 Jeffery   535 grain bullet @ 50 meter 1732
Ready formed cases and die-sets for the 458 SABI are available.

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