Returning to an old favourite, Byron Pace details why the .300 Win Mag is still at the top of the pile despite the emergence of newer, faster contenders
There are some cartridges I keep coming back to. For all the new evolutions of design and powder technology, they just work, and have a history so ingrained in hunting culture, it makes it very hard to look past them.
When picking a cartridge for hunting, the decision does not, or at least should not, lie solely with the capabilities of the round. It may be fine to use an obscure wildcat if hunting a stone’s throw from home, but for the travelling hunter this could cause a whole world of heartache. If your ammo doesn’t arrive, you need more or have problems, it could prove difficult to obtain new ammo for anything other than the well known stalwarts.
The .300 Win Mag is a superb cartridge in terms of what it delivers, and has been around for long enough, and carries enough popularity today, to make it unlikely to cause issues of supply. Yes there are newer, more efficient rounds out there, and no, I have never owned a rifle in .300 Win Mag. I have, however, shot it plenty, and hunted with numerous people who have used it in anger. Launched some 38 years before the Winchester, the highly respected .300 H&H Magnum covered similar ground, seeing widespread use across Africa to high acclaim, while also winning the 1,000- yard Wimbledon Cup in 1935. Today its use has diminished, and the .300 Win Mag, introduced in 1963, has come to the fore.
Based on the .375 H&H, the blown-out and shortened case of the .300 Win Mag sports a much steeper shoulder than the earlier .300 H&H, which also took the same parent case. The body of the case was stretched by 0.12in over equivalent calibres, and though unconfirmed, it was speculated that Winchester oversized the case to allow rifles already chambered .30-338 and .308 Norma to be easily reamed out to fit 300 Win Mag dimensions.
In any event, the .300 Win Mag has seen global success, becoming the calibre of choice for those reaching shots required on antelope on the open plains, or cross-canyon shots on perilously perching sheep and goats. It truly is an excellent sheep calibre, if not the best. Equally, it provides adequate energy to cope with the biggest bear, pushing a 180gn bullet with 3500ft/lb ME, while also providing acceptable varminting capabilities with the flat-shooting 130gn head (rising just 0.9in for a 200-yard zero, with a 5in drop to 300 yards).
Today it is hard not to feel that the calibre has been outclassed ballistically with the advent of the .300 Weatherby Magnum and more recently the .300 Rem Ultra Magnum. The numbers are telling. Taking the same 180gn bullet with factory loads, will see the .300 Rem Ult Mag drop 5.6in at 300 yards, compared with 6.2in and 7in for the Weatherby and Winchester respectively (based on a 200-yard zero). Over 400 yards the Remington trumps the Winchester by over 4in, delivering considerably more downrange energy at 2400ft/lb – 200ft/lb more than the Weather by and 600ft/lb more than the Winchester. This is achieved primarily through the larger case capacity – 19 per cent more than the Winchester – owing to the fatter body of the parent .404 Jeffrey case. This translates into more powder and higher velocities, screeching out the 180gn round at over 3200fps compared with an MV just on the 3000fps mark for the other two.
But you can’t squeeze out all that performance without having to pay for it. The equal and opposite reaction to this down-range magic is felt by the shooter in the form of some unpleasant recoil. In my view, it’s a severe punishment for only a modest improvement on the .300 Win Mag. Given a 260-yard zero, the .300 Win Mag will still shoot inside a 6in killzone out to 300 yards. You will gain a few more yards with the Ultra Mag, but even out at 350 yards we are only talking a 1.5in advantage, and with a drop of 7-8in, this would have to be taken into account anyway. Serious advantage is only seen in ultra long-range shots, which have questionable ethics at any rate.
The .300 Win Mag provides an excellent compromise, with a level of accuracy that was never in question, having seen use as a sniper round while also winning multiple 1000-yard competitions. Bigger is not always better and the .300 Win Mag has proven itself over time.
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