Winchesters .300 WSM: Short And Fat Versus Long and Slim

When we compared this new round, and the rifle for which it is chambered, to existing 06s and .300 Winchester Magnums, we were left wondering: Whats the point?


Winchester’s .300 WSM seems a bit strange to us. Its purpose would seem to be the achieving of a somewhat lighter rifle while maintaining the approximate performance of the .300 Winchester Magnum. With its 1/2-inch-shorter cartridge length, the .300 WSM’s action can be half an inch shorter, too. Also, there’s the matter of a shorter bolt throw, which implies a faster-operated rifle. Independent tests of these points by some friends of Gun Tests indicated they are not necessarily true. (They found identical rifle weights and bolt-operation times in a casual test of on-hand rifles.)

The standard, belted .300 Winchester Magnum holds more powder than the .300 WSM. We took empty cases of .308, .30-’06, .300 WSM, and .300 Win Mag and poured them full of a fine-grained ball powder, and weighed the results. We found the .308 held 54 grains, the ’06 held 68, the .300 WSM held 80, and the .300 Win. Mag. held 85. Therefore, the .300 WSM cannot be quite up to the ultimate performance of the Win. Mag., but the differences would be slight. Tests of the .30-06 with Hornady’s Light Magnum loads indicated a velocity with the same-weight bullet (180 grains) not far behind that of the .300 WSM.

The beltless .300 WSM is based on the .404 Jeffery head size, and of course headspaces on its shoulder. That makes the case very close to the same outside diameter as the belt on a belted case. Any bolt-action rifle that can handle a standard belted-magnum case can handle a case based on the .404 Jeffery head size. The Dakota company was among the first to utilize this case-head size for its proprietary cartridges, and the idea is a very good one. You don’t really need that belt for anything.

Having established that, why didn’t Winchester come up with a longer, and more powerful .30-caliber magnum, much like Remington’s Ultra? We don’t know, but to compound our confusion we have heard that Remington plans to bring out a short .30 magnum similar to the WSM Winchester. To some of us, this is the third reinvention of the wheel. With the very successful and easily found .300 Win. Mag. available, why would two major U.S. manufacturers bring out two new cartridges to compete against it? Have they not heard of the .30-’06?

We acquired a new stainless Winchester Model 70 in .300 WSM caliber to see what the new cartridge offered. We also referred to previous tests of rifles in .30-’06 and .300 Winchester Magnum to see what it was up against. Here are our findings.

Winchester Model 70 .300 WSM, Stainless, $813
Winchester offers four versions of this rifle in the Model 70. They are the Featherweight, our Stainless, a Laminated, and one called the Coyote. The claimed weight of the Winchester Featherweight ($754), per Winchester’s website, is 7.5 pounds. The weight for the Stainless version is given as 7.25 pounds, which is what our test rifle actually weighed. The Laminated version ($777) has an estimated weight of 7.8 pounds. Winchester’s so-called Featherweight apparently weighs more than our test rifle, and that’s, at the very least, misleading. The Coyote is listed at 9 pounds, and at $720 is the least costly Model 70 in this caliber. But you don’t get controlled feed. The Coyote has a push-feed bolt. All the rest are controlled-feed, and all versions have 1:10-inch-twist barrels and three-round magazines. There are also 7mm and .270 versions of the cartridge.


The matte, silvery-gray appearance of the stainless-steel metalwork was pleasantly contrasted by the matte-black synthetic stock. The stock had adequate checkering, and a black rubber butt pad that was large enough, but not soft enough. It was firm to the point of being hard. If ever a rifle needed a good recoil pad, this would be it, we thought. The large size of the pad spread recoil, and our heavy winter coats helped dissipate recoil, but we’d put a Sorbo-Coil or Decelerator pad on this rifle. The rifle had a mystery rattle within the stock. Under normal use we could not hear it, but a good shake told us something was loose inside the stock. We left it alone. Two stainless QD sling studs were in the usual places on the stock.

Workmanship was very good to excellent throughout. The appearance was of a clean, simple rifle with no frills. The Winchester name on the left side of the action was understated and classy. The ring of checkering around the bolt handle could either help those who like such things, or be ignored by those who don’t. The bolt was jeweled, the only sparkling touch on the rather plain rifle. Jeweling can hold microscopic particles of oil, so it was a functional addition as well.

We checked the action bolts for tightness and found something we didn’t altogether like. The bolts had Phillips-head notches. Our preference is very greatly in the direction of simple screwdriver slots, and we suspect we’re not alone. Allen heads can easily strip, but they’re better than these Phillips-head bolts, which required great hand pressure and a perfect-fitting driver to get a good purchase.

Three rounds would go into the magazine, and we could close the bolt easily over a fourth. The magazine follower had a raised portion on its rear one-third, that was contoured to press the first-loaded cartridge firmly to the right against the underside of the right rail. The floor plate of the magazine was the usual hinged Winchester item, opened by a button in the front of the trigger guard. It came open readily, but not easily, per design. The safety was the usual three-position swinging unit. It worked perfectly. One nice feature of that design is the ease of removing the firing pin, accomplished by placing the safety in the middle position, removing the bolt, pressing a button and unscrewing the pin.

We took the firing pin out of the rifle and checked for cartridge feed and function before any test firing. Feeding from any angle and at any speed was flawless, and though there was a slight bit of hesitation as the fat cases slid home into the chamber, we couldn’t complain. With the coned breech and large chamber opening, it would be a very odd cartridge or situation that would cause a bullet to hang up on entry into the chamber. Ejection was positive at any speed and position. Because of the controlled-feed system, ejection power depended on how hard we worked the bolt.

We believe Winchester had the right idea bringing out this .404-Jeffery-based case to approximately equal the belted .300. There’s a ground-swell of shooter movement against belted cases in recent times, and this new setup might make someone look to a Winchester instead of, say, the much hotter and more specialized Remington .300 Ultra, once it’s realized the .300 WSM gives performance that should be adequate for almost all North American hunting conditions.

We think it’s possible to build a rifle slightly lighter around the short case than the much longer .300 Win. Mag. A relatively light .300 Magnum can be a good idea, and would reduce the bulk carried on difficult hunts without giving up rifle power.

The trigger was a bit stout at 4.4 pounds, but clean and fully acceptable. And of course it’s adjustable. We mounted a 2.5X Burris scope and proceeded to the range. We tested with only one load, which was all we could get locally. It was Winchester’s 180-grain Power Point, with CXP3 bullet. The first shot told us recoil would not be a problem with this rifle. There was enough rifle weight at 8.0 pounds, with scope, and the excellent stock shape let us fire the rifle without discomfort. This led us to believe we had about the power of a .30-’06 in our hands, rather than a .300 Magnum. The chronograph told us we were slinging 180-grain bullets downrange at a click under 3,000 fps. Specifically, we got 2,977 fps over a ten-shot average.


We suspected these loads were about as hot as you would want to go with this case. Extraction was not sticky, but there was a distinct effort involved in lifting the bolt handle. The SAAMI maximum pressure of this cartridge is 65,000 psi, same as that of the .300 Win. Mag. Winchester claims that within that pressure, the short, fat case gives the same ballistics as the greater-capacity belted magnum version, but we’ll hold our opinion for awhile yet. Fired cases ejected perfectly. There were no problems with feeding or ejection during our actual test firing with live ammo.

Our first three shots at 100 yards struck into a group that measured 0.8 inch. From there they opened up slightly, and we ended with an average of 1.6 inches, plenty good enough for a 2.5X scope mounted on a powerful rifle that was actually tested in a snowstorm. We believe better conditions would have given a marked improvement in this rifle’s accuracy showing. A greater selection of ammunition and/or careful handloading would, we believe, get the maximum out of this rifle. The bore was noticeably excellent-looking when viewed under magnification.

We did not mind the recoil during our bench testing, though as noted above, we could have done with a softer recoil pad that would have absorbed more of the punch. We found the rifle to be pleasant, reliable, very reasonable, and shooter-friendly. There were no nasty surprises, and we liked the rifle quite a bit. We suspect shooters will too, and might come to prefer the shorter case with nearly the same performance as the .300 Win. Mag.

However, if you already have a good .30-caliber rifle, even a .308, we see no great need for this one. If you have a .308 and want more killing power, what you really need is more bullet weight, and that spells larger-diameter bullets. This same short, fat case in .338, with 250-grain bullets, might be a real dandy.

The long-range deer hunter might be better served with 150-grain bullets in the .300 WSM, and we would expect a velocity of around 3,200 fps. Winchester claims 3,300 for the Silvertip load, which is entirely believable because of their very accurate claim of 2,970 fps for the 180, which our ammo/rifle actually exceeded.

It should be possible to build a rifle considerably lighter than our test sample around this cartridge, for an all-up weight of around 7.5 pounds with scope. For the serious hunter or shooter who is accustomed to some recoil, we could see the benefits of such a rifle. For the average shooter, we felt this weight, 7.2 pounds bare, was about right.

Savage 110 FP Tactical .300 Win. Mag., $429
The pick of our April 2001 test of .300 Win. Mag. rifles was the Savage 110 FP Tactical rifle. Its cost was about half that of the Model 70 Winchester WSM, though street prices would bring them a bit closer together. The tested Savage was more of a heavy-, or medium-heavy-barrel rifle than a hunting arm, weighing in at 8.5 pounds without scope. Our test .300 WSM was 8 pounds scoped. You can get a lighter rifle from Savage in .300 Win. Mag., so the question becomes more one of velocity than features.


Our test of a trio of .300 Winchester Magnum rifles did not utilize any ammunition with the most-common, in this caliber, 180-grain bullets. Closest was 190-grain fodder, which gave approximately 2800 fps out of the two 24-inch barrels tested (Savage and Winchester). Out of the 26-inch barrel Remington that load achieved 2863 fps. Clearly the .300 WSM, which gave 180-grain bullets 2,977 fps in our one Winchester test load was at least a good match for bullet speed, extrapolating from our data. But in selected loads, and certainly in handloads, the outcome would surely favor the .300 Winchester Magnum, and the price would make a rifle like the Savage hard to beat.

Savage M111F .30-06 Springfield, $395
In May 1999 we tested five sporter ‘06’s, all but one of which had 22-inch barrels. The odd one had a 24-incher. The heaviest bullet we tested weighed 165 grains, only 15 grains lighter than the bullet tested in the .300 WSM. The average of all five rifles’ velocity with Winchester’s 165-grain PSP bullet was 2,955 fps. That’s almost the exact velocity obtained by the brand-new, super-hot-loaded .300 WSM with 180-grainers. The 24-inch rifle did not get the highest velocity with this load. Two rifles beat it for velocity. It’s pretty easy to get an idea what the ’06 would do with 180-grain bullets by intelligent extrapolation.


In this test as well, a Savage won, this time the M111F, a gun which more closely matches the .300 WSM in weight at 6.5 pounds empty and unscoped.

As we said, if we already had a .30-’06 we would not go looking for a .300 WSM.

Gun Tests Recommends
Winchester Model 70 .300 WSM, Stainless, $813. Conditional Buy. Would we buy the .300 WSM? Not if we already had a .300 Win. Mag., or even a .300 H&H Mag. Not if we already had a good .30-’06. However, even if we had a good .308, we’d be tempted to have the .300 WSM in a light rifle.

If we had no rifle at all in this performance class, we’d look long and hard at the .300 WSM for an all-around hunting rifle for most North American game, but we’d temper that choice by checking for local ammunition supply along the way. Compared to the availability of .30-06 bullet weights and styles and the ‘06’s affordability and proven performance, the. 300 WSM has a difficult opponent to overcome.






  1. 300wsm May end up being the lone survivor of thee Winchester Short Magnums. A couple of 1000 yard records were set with the cartridge. It got an honorable mention in a “top selling” article. Bench rest shooters and hunters like the 300wsm. Some short range hunters look for an excuse to own one. I thought like the author though. Having the 30-06 dissuaded me from getting a 300wsm. That’s why I went for the 325wsm. And even though 8mm is similar in performance to a 30-06, I needed an excuse to buy a couple of new rifles and
    try something different than the old faithful. So I bought two 325 rifles- lol.
    So maybe it’ll be practical to barrel change to 300wsm one day. Over all WSM cartridges come in lightweight rifles,are relatively flat shooting, give more down range power than their non magnum counterparts, easy to reload, and are accurate. Starting to look like the 300wsm
    may be here to stay. Even if they come out with more .30 caliber cartridges. Which is more than likely- lol.


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