As a baseline, three factory loads intended for quality big and dangerous game were checked out. Recognizing that few will be hunting Elephant or Cape Buffalo, the purpose of this live fire is to check against specification performance, before moving on to handloads.
A 500 grain expanding bullet, as represented by the first two loads below, can dispatch a large bear or moose. However, there is a good deal of overhead in recoil and firearm weight, when less would do and power and flatness of trajectory beyond 300 yards could easily be surpassed by a lesser round.
With Federal 500 grain Trophy Bonded ammo, the 458 Winchester has a muzzle velocity of 2090 fps and a muzzle energy of 4850 ft-lbs. At 200 yards, this has dissipated to 1580 fps and 2775 ft-lbs. A Hornady 338 Winchester Magnum 225 grain load has a muzzle velocity of 2840 fps and muzzle energy of 4029 ft-lbs. At 200 yards, the 338 Win Mag is still moving 2490 fps with 3097 ft-lbs of kinetic energy. On a 200 yard zero, the 458 Win Mag rises 4.4″ at 100 yards and drops -17.5″ at 300 yards. The 338 Win Mag rises only 1.7″ at 100 yards and drops only -7.3″ at 300 yards.
| Cartridge | Bullet Grains |
Type | Rated MV FPS |
Rated ME Ft-Lbs |
Actual MV FPS |
Actual ME Ft-Lbs |
| Federal Premium Safari | 500 | Swift A-Frame | 2090 | 4850 | 2164 | 5200 |
| Federal Premium Safari | 500 | Trophy Bonded | 2090 | 4850 | 2137 | 5071 |
| Federal Premium Safari | 500 | Woodleigh Solid | 2050 | 4665 | 2048 | 4658 |
The Winchester Model 70 Safari Express did not have any difficulties meeting and even exceeding ammunition rated velocity over a calibrated chronograph. At approximately 76 ft-lbs of recoil, I would classify it as brisk, but not at the retina detaching level of some of the very heavy big bores. A good amount of ejecta for a smokeless cartridge, which makes me wonder what a couple more inches of barrel would bring to the party. Judging from the kinetic energy numbers, probably nothing necessary.
A note on scope mounting. The Model 70 African Express has 0.330″ hole spacing on the aft receiver ring rather than typical 0.440″ to accommodate the longer magnum action bolt travel.The Warne number is M902/802 for two piece bases. The rifle definitely deserves a scope unless what you are planning on hunting would only give you a view of an eyeball at 50 yards. I shot factory ammo at 50 yards with the rifles metallic sights. Other than being… jostled around a bit. the sights are actually very precise in alignment and clear against a target. As long as game is larger than 3/4″ at 50 yards, scoring should not be a problem.
From another perspective…
With the close in, heavy hitting end of the bullet weight range taken care of with factory ammunition, lighter weight bullets that might be more suitable to North American game were explored, along with one 500 grain expanding bullet to see how load levels, pressure and velocity, came to matching factory performance.
The 350 grain Hornady Interlock Round Nose is listed by Hornady for use on thin skinned African game and any North American Game. There is a 300 grain flat nose, but that is intended for 45-70 velocity levels. Hornady has the 350 grain loaded to 2500 fps.
The 350 grain Hawk Precision pictured has an 0.035″ thick jacket which is good for large body thin skinned game. Hawk also makes a 0.050″ thick jacket version.
The 400 grain Swift A-Frame, one of their Heavy Rifle Bullets, is loaded to 2400 fps in the 458 Winchester Magnum. The bullet will increase is diameter by 30% at 250 yards at 1661 fps retained velocity and 75% at 100 yards 2085 fps retained velocity. Deep penetrating and between 98% and 99% retained weight.
The 500 grain Hornady DGX Bonded has an 0.098″ copper clad steel jacket over lead core construction. Hornady recommends it for big and dangerous game, deep penetration and expansion to 1.5x-2x within 150 yards. Specifically, up to 1500 lbs thin skinned game and cape buffalo.
Adjusted for measured component dimensions, seating to cannelure and checking with a COL clearance gauge the assemblies looked like this:
| Bullet | Type | Weight Grains |
Bullet Length” |
COL” |
| Hornady | SPRN | 350 | 0.915 | 2.950 |
| Hawk | SPRN | 350 | 0.890 | 2.970 |
| Swift | SPFN | 400 | 1.140 | 3.220 |
| Hornady | SPRN | 500 | 1.395 | 3.310 |
Handload Data
Warning: Bullet selections are specific, and loads are not valid with substitutions of different bullets of the same weight. Variations in bullet length will alter net case capacity, pressure and velocity. Primer selection is specific and primer types are not interchangeable. These are maximum loads in my firearms and may be excessive in others. All loads should be reduced by 5% as a starting point for development where cartridges have greater than 40 grains in capacity and 10% for cartridges with less than 40 grain capacity following safe handloading practices as represented in established mainstream reloading manuals. Presentation of these loads does not constitute a solicitation for their use, nor a recommendation.
| Cartridge – 458 Winchester Magnum |
|
| Firearm | Winchester Model 70 |
| Barrel Length | 24.00″ |
| Min – Max Case Length | 2.500″ +0.000″/-0.020″ |
| Min – Max COL | 3.280″ – 3.340″ |
| Primer | CCI 250 |
| Bullet Diameter | 0.4590″ +0.000″/-0.0030″ |
| Reloading Dies | Hornady |
| Bullet Type | Bullet Weight Grains |
Net H2O Grains Capacity |
COL” | Powder Type | Powder Charge Grains |
Muzzle Velocity fps |
Muzzle Energy ft/lbs |
100 YD 3 Shot “ |
| Hornady SPRN |
350 | 75.6 | 2.950 | H322 | 78.0 | 2615 | 5316 | 1.0 |
| Hornady SPRN |
350 |
75.6 | 2.950 | RS X-Term | 80.0 | 2508 | 4890 | 1.1 |
| Hawk Precision | 350 | 77.9 | 2.970 | H322 | 77.0 | 2569 | 5130 | 0.9 |
| Hawk Precision | 350 | 77.9 | 2.970 | RS X-Term | 80.0 | 2464 | 4720 | 1.2 |
| Swift A-Frame | 400 | 77.9 | 3.220 | H322 | 76.0 | 2446 | 5315 | 1.1 |
| Swift A-Frame | 400 | 77.9 | 3.220 | RS X-Term | 78.0 | 2397 | 5104 | 1.0 |
| Hornady DGX | 500 | 70.0 | 3.310 | RS X-Term | 72.0 | 2089 | 4846 | 1.2 |
| Hornady SPRN |
350 |
75.6 |
2.950 |
Trail Boss |
22.5 |
1250 |
1215 |
1.0 |
Handloading was very straight forward. Brass was new Norma brand. The Lee sizer squeezed them down a bit, but not enough to cause significantly compressed loads. Feed from the magazine was slick… flawless, but the claw extractor did not allow directly chambering, so it was a matter of popping a round into the mag well and closing the bolt which is probably less fumbling under pressure.
The warning ahead of the load data stands, but I will make a couple of brief comments about the outcome. I think my favorite was the Swift A-Frame with H322, but the bolt face did tend to leave a lasting impression on the face of the case head. The 350 grain light loads were lots of fun and relatively inexpensive… and quite accurate. For deer load, I might be temped to load 300 grain flat nose bullets intended for the 45-70, thin enough jacket to expand at low velocity. Powder would be 38.0 grains of IMR 4198 with a COL of 2.930″ for 1850 fps.
Above, 100 yard target with Swift 400 grain A-Frame. It may be even more accurate… if I could just get my brain to pay no attention to the muzzle blast and recoil. It was a fun day just because big bore, big boom and nice rifle, but not one I want to do again tomorrow. Lots of shots fired between chronograph and pulling targets. So what does that bullet look like over the longer haul?
| 458 Winchester Magnum Best Zero Results | |||||||
| Near-Zero – Yards | 21 | Mid Range – Yards. | 112 | ||||
| Far-Zero – Yards |
195 | Max Ordinate – Inches | +3.0 | ||||
| Point Blank – Yards |
207 | ||||||
| Best Zero : Range 0 – 300 yards 400 Grain Swift A-Frame | ||||||||
| Yards | 0 | 50 | 100 | 150 | 200 | 250 | 300 | |
| Velocity – fps | 2446 | 2283 | 2127 | 1978 | 1835 | 1698 | 1570 | |
| Energy – ft.-lbs. | 5313 | 4629 | 4018 | 3473 | 2989 | 2560 | 2189 | |
| Momentum – lbs-sec | 140 | 130 | 122 | 113 | 105 | 97 | 90 | |
| Path – in. | -1.50 | 1.55 | 2.93 | 2.39 | -0.37 | -5.73 | -14.10 | |
If that isn’t a solid varmint rifle, it has to be a heck of an elk rifle. A 207 yard point blank range on a +3″ ordinate and only 14″ to account for at 300 yards and still pulling 2189 ft-lbs of kinetic energy. Yes, I did just rear off my own chart. Thank you for noticing. My point is, and I believe I have made many, is that the 458 Winchester is more than just a stopper for a 50 yard hard charger. It is a rifle that can be put to work on large thin skilled game.
Conclusions without jumping…
It may have taken a long time to get here, but I am glad I got to work with this Winchester and I am sorry I did not get to shoot the original Winchester Model 70 African when I was a kid… Yeah, I know, baby goats. That said, it feels like a classic Winchester, the quality is excellent throughout and it is good shooting and good looking. For folks who like to carry large, it is a heck of a rifle and at a not bad price.
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