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Winchester’s .270 & 7mm Short Magnums

by G&A Staff   |  January 4th, 2011 14

Winchester’s second .270-caliber cartridge in its history is also its second entry in the Winchester Short Magnum series. And a new 7mm WSM is here, too.


The new .270 WSM is initially available loaded with 130-grain Ballistic Silvertip, 140-grain Fail Safe, and 150-grain Power-Point bullets while the new 7mm WSM is available in 140-grain Ballistic Silvertip, 150-grain Power-Point, and 160-grain Fail Safe loadings.

Jack O’Connor would have loved the new .270 Winchester Short Magnum (WSM). The longtime shooting editor of Outdoor Life, and one of the most widely read and influential firearms gun writers of all time, O’Connor spent most of his professional life working to popularize the long-action .270 Winchester. He regarded it as the best all-round cartridge ever designed for all North American big game and African plains game. The .270 versus .30-06 debate he engendered still goes on today.

The new .270 WSM incorporates all of the positive attributes of the original .270 design and much more. In my view it is even better than the original, for all the same velocity and energy reasons O’Connor liked. The new .270 WSM packs 200 fps more velocity and 15 percent more energy than the standard .270 Winchester behind all equivalent-bullet loadings in a half-inch shorter case that will work in a standard-length short-action bolt mechanism. Initial .270 WSM loadings will be available in the Winchester Supreme line with 130-grain Ballistic Silvertip and 140-grain Fail Safe bullets and in the Super-X category with 150-grain Power-Point bullets. They should reach gun store shelves during the early spring of 2002.

New A-Bolt rifles will be available from Browning in lightweight 61/2-pound, 23-inch Stainless Stalker, Composite Stalker, Hunter, and Classic Hunter models. U.S. Repeating Arms (USRAC) will offer 71/4-pound Winchester Model 70s with 24-inch barrels in Classic Featherweight, Classic Stainless, and Classic Laminated versions along with the new nine-pound push-feed short-varmint Coyote model.

And at the same time, Winchester is also introducing the equally new 7mm Winchester Short Magnum (also in three loadings: 140-grain Ballistic Silvertip, 150-grain Power-Point, and 160-grain Fail Safe), which stands in the same relationship to the long-action 7mm Remington Magnum as the .270 WSM stands to the .270 Winchester and as last year’s .300 WSM stands to the long-action .300 Winchester Magnum–slightly more powerful and more ballistically efficient in a short-action case. (The same models of Browning and USRAC rifles are being simultaneously introduced for the 7mm WSM and the .270 WSM.) action bolt mechanism. Initial .270 WSM loadings will be available in the Winchester Supreme line with 130-grain Ballistic Silvertip and 140-grain Fail Safe bullets and in the Super-X category with 150-grain Power-Point bullets. They should reach gun store shelves during the early spring of 2002.

New A-Bolt rifles will be available from Browning in lightweight 61/2-pound, 23-inch Stainless Stalker, Composite Stalker, Hunter, and Classic Hunter models. U.S. Repeating Arms (USRAC) will offer 71/4-pound Winchester Model 70s with 24-inch barrels in Classic Featherweight, Classic Stainless, and Classic Laminated versions along with the new nine-pound push-feed short-varmint Coyote model.

And at the same time, Winchester is also introducing the equally new 7mm Winchester Short Magnum (also in three loadings: 140-grain Ballistic Silvertip, 150-grain Power-Point, and 160-grain Fail Safe), which stands in the same relationship to the long-action 7mm Remington Magnum as the .270 WSM stands to the .270 Winchester and as last year’s .300 WSM stands to the long-action .300 Winchester Magnum–slightly more powerful and more ballistically efficient in a short-action case. (The same models of Browning and USRAC rifles are being simultaneously introduced for the 7mm WSM and the .270 WSM.)


The first 100-meter three-shot group with the .270 WSM (130-grain Ballistic Silvertip) and a Browning lightweight sporter rifle measured 0.80 inch. The second three-shot group with the same loading and rifle measured 0.79 inch.

The .270 WSM Is the Big News
Both new short-action cartridges are going to be very popular. However, the .270 WSM will attract the lion’s share of attention from the shooting sports media, and it is sure to cause the most “buzz” in gunshops around the country.

Why?
First, let’s acknowledge that the 7mm is a very popular caliber. So popular, in fact, that there are already a lot of 7mm cartridges already out there (long action and short), including the 7mm Shooting Times Westerner; the 7mm Weatherby Magnum; the 7mm Remington Magnum, which turns 40 this year; the .280 Remington; the 7mm-08; the still-popular 7mm Mauser, even the WSM-similar .284 Winchester. The list goes on.

On the other hand, the .270 is also one of the world’s most popular cartridge calibers, with tens of thousands of rifles and shooters around the globe. But with the exception of the proprietary .270 Weatherby Magnum, the original .270 Winchester remains the only commercially available .270 cartridge. There have never been any other .270 commercial long-action loads, either standard or “magnum- ized,” and no commercial .270 short-action loads of any stripe. (Experimental wildcatters, of course, have collectively already tried every imaginable caliber-case-configuration combination in the world at one time or another.) So the short-action .270 WSM is truly an idea that’s been waiting a long time to happen.


Each of the new .270 WSM loads has a higher velocity than the same bullets in conventional .270 Winchester counterparts; .30-06 and .308 cartridges (R) are shown for comparison.

The original .270 Winchester cartridge dates from Winchester’s introduction of it in 1925 for the Model 54 bolt-action rifle. The unique caliber (.277 inch actual) was “purposely invented,” as it’s said, to avoid being similar to anything already existing in Europe or Britain at the time. Cartridge authority Jack Barnes thinks Winchester engineers might have been influenced by a contemporary Chinese .277 cartridge, but I think that’s stretching it. The .270 Winchester case was simply a necked-down .30-06, making the .270 one of the first of a long line of .30-06-derived cartridges. Primarily renowned for long-range, flat-shooting accuracy (hence its image as a “Western” cartridge), the .270 Winchester continues to grow in
popularity and ranks today among Winchester’s five top-selling rifle cartridges. The “other .270,” Roy Weatherby’s .270 Magnum, started off as a wildcat in 1943 in a necked-down and sharp-shouldered .300 H&H case. Weatherby’s success hunting with it is what led him to go into the commercial gun business in 1945, and the .270 Weatherby Magnum remains one of his company’s all-time largest sellers.

The new .270 WSM and 7mm WSM are based on the original short, fat, beltless .300 WSM case, which was developed by Winchester and Browning sui generis for the new WSM series. (All further WSM introductions will be based on this case as well.) Like the .300 WSM, these two new WSM cartridges provide precise headspacing on the shoulder and, in spite of the somewhat abrupt shoulder angle, feed extremely well in the Browning and Winchester rifles I have handled. This jug-shaped “semi-PPC-type” case design has become firmly established in the world of hyperaccuracy benchrest shooting in recent years because of the improved load density and uniformity of burn that occurs in a short, fat case as opposed to a relatively long, skinny case. With the WSMs, Winchester has now taken this high-level competition design concept and translated it to field and sport-hunting applications (not unlike the way that successful high-end racecar technology eventually finds its way into your family minivan).

Moreover, the improved efficiency of propellant burn in a shorter/fatter case profile also allows the WSM to achieve higher velocities with equivalent bullets than their longer case counterparts–with less powder mass. For example, the propellant charge weight behind a 180-grain Fail Safe .300 WSM load is 68.0 grains; the charge weight in a 180-grain Fail Safe .300 Winchester Magnum load is 81.0 grains. The .300 WSM clocks 2970 fps at the muzzle; the .300 Winchester Magnum clocks 2960 fps.


The Browning A-Bolt features a tang-mounted manual safety, a visible cocking indicator, a wide grooved trigger, a hinged magazine floorplate, and an easy-to-operate external bolt-release latch.

In technical terms, smaller powder charge weights translate into smaller “ejecta mass,” which means less absolute recoil. So the new .270 WSM and 7mm WSM cartridges, like the .300 WSM, actually provide more velocity and less recoil with the same exact bullets than the longer case predecessor .270 Winchester, 7mm Remington Magnum, or .300 Winchester Magnum. More velocity, less recoil! I know this sounds impossible, but it is immediately apparent when shooting. The first time I sat down at the benchrest to fire a lightweight WSM Browning Synthetic Stalker, I expected to get beat up right fiercely. But it wasn’t bad at all, not nearly as punishing as one of the long-case originals would have been, and I walked away three boxes of ammo later without discomfort. No wonder the .300 WSM took off last year like a house afire.

Performance To Spare
Another benefit of WSM case design is enhanced accuracy that also comes from improved ignition and burn uniformity. Increased burning uniformity means more consistent bullet launch velocity round to round, which in turn means tighter groups, assuming a bullet that’s stable in flight at that velocity. Again, the proof is in the shooting. When Winchester engineer Glenn Weeks (who has shepherded the new .270 WSM and 7mm WSM to completion) came up to PASA Park to try the new .270 WSM loads through real rifles on a real range for the first time, his very first three-shot group with the 130-grain Ballistic Silvertip .270 WSM load went 0.80 inch at 100 meters. Winchester’s communications representative Kevin Howard then sat down and put three rounds of the same load into 0.79 inch.

These results were gained from a stock Browning 23-inch lightweight Stainless Stalker hunting rifle fitted with a 3-9X Kahles hunting scope. My three-group average with the same load through the same gun measured 0.95 inch. Incidentally, when my Shooting Times colleague Layne Simpson fired his first three rounds of .300 WSM 180-grain Fail Safe through a Stainless Stalker on an Alaskan hunt last year, they went into 0.68 inch at 100 yards, two in virtually the same hole. These loads really shoot, and the accuracy benefits of the increased rigidity available in a short-action rifle are also not to be overlooked.

In terms of comparative performance figures for the new WSMs and their long-case predecessors, consider the following nominal catalog specifications. The 130-grain Ballistic Silvertip bullet in the regular .270 Winchester has a muzzle velocity of 3050 fps. In the .270 WSM, the same bullet has a muzzle velocity of 3275 fps. Zeroed at 200 yards, the 130-grain Ballistic Silvertip .270 WSM drops 5.5 inches low at 300 yards and 16.1 inches low at 400. The 140-grain Fail Safe bullet in the .270 Winchester has a muzzle velocity of 2920 fps; the .270 WSM ramps this up to 3125 fps. The 150-grain Power-Point bullet in the Super-X line has a muzzle velocity of 2850 fps in the original .270 Winchester, 3150 fps in the .270 WSM.


Browning lightweight synthetic-stock Stainless Stalker A-Bolt rifles with Kahles 3-9X scope were used for the first hunt with the new .270 and 7mm WSM cartridges.

In application, Winchester rates the 130-grain Ballistic Silvertip .270 WSM for deer, antelope, and thin-skinned big game. The Fail Safe bullet, with a deep hollow nose that upsets over a wide range of velocities and a rear lead core held in place and reinforced by a steel insert, retains virtually 100 percent of its original weight on impact and performs like a conventional-core heavier bullet in any given caliber or weight. In the .270 WSM the 140-grain Fail Safe is intended for heavier game, and the 150-grain Winchester Power-Point is intended for hunters who want even more bullet weight for their particular quarry. Turning briefly here to the new 7mm WSM, it too exceeds the performance of its “antecedent” cartridge, the longer belted 7mm Remington Magnum round, in every ballistic category, again because of the efficiency of the new case design and the uniformity of ignition and powder burn. In addition to the advantages shared with the .270 WSM, the 7mm WSM (like the .300 WSM) also benefits from improved accuracy due to being headspaced on the case shoulder instead of the case belt.

After a day at PASA Park shooting the .270 WSM Browning Stainless Stalker with early samples of the 130-grain Ballistic Silvertip and 140-grain Fail Safe loads (results are listed in the chart), I joined Winchester’s Mike Jordan and Greg Kosteck and Browning’s Scott Grange, along with a group of other writers, for a mule deer hunt in the Abajo Mountain foothills of southeastern Utah. The rugged and intermittently open-and-thicketed terrain offered a superb test bed for the lightweight Browning Stainless Stalker rifle and the new .270 WSM. (I made sure I got to hunt with the same rifle Glenn and Kevin used back at PASA Park to shoot those superb first groups.) Others in the party had the opportunity to use the new 7mm WSM
as well.

On the opening evening of the hunt, I encountered a beautifully proportioned five-pointer (5×5) in full velvet feeding in a saffron field at about 150 yards distance. I judged his spread at only about 22 inches, but his “look” was just right. He was quartering toward me, left shoulder forward. The rifle was loaded with the 130-grain Ballistic Silvertip, which is my choice for mule deer rather than the deeper penetrating Fail Safe, so I held just slightly off the bony point of his shoulder for a direct entrance into the chest cavity and took the shot. I heard the loud slap of the bullet impact immediately on top of the muzzle blast even before the muzzle had even reached its peak arc. Fast. The deer staggered two steps sideways away from the impact and collapsed.

The bullet transected both lungs and the liver, leaving a pulverized wound channel with more than six inches of visible trauma diameter. As we approached the animal, I noticed a visible lump on the hide just at the rear of the rib cage on the offside. It was the bullet, stopped just beneath the skin. As you can see from the photo, the Ballistic Silvertip performed exactly as designed–full explosive upset and shed of the nose core, with the heel core behind the partition still intact. Actual measurement proved the rack width to be 23 7/8 inches, so my quick field estimate wasn’t too far off. When I got back into camp, the Winchester people confirmed what had occurred to me while driving back in–I had just put down the very first animal ever taken with the .270 Winchester Short Magnum cartridge. Somehow, I like that.


How The .270 WSM Compares
Factory load Muzzle Velocity (fps) Muzzle Energy (ft-lbs)
.270 WSM, 24-inch Test Barrel
Win. 130-gr. BST 3275 3096
Win. 140-gr. FS 3125 3035
Win. 150-gr. PP 3150 3304
.270 Winchester, 24-inch Test Barrel
Win. 130-gr. BST 3050 2702
Win. 140-gr. FS 2920 2651
Win. 150-gr. PPP 2950 2900
.270 Weatherby Magnum, 26-inch Test Barrel
WBY 130-gr. Partition 3375 3288
WBY 140-gr. BT 3300 3385
WBY 150-gr. Partition 3245 3507

 

Other hunters’ experiences later in the week were similar, and the several coyotes taken during the week at distances out to 400 yards were turned inside out. Even the heavier 140-grain Fail Safe bullet was explosive on coyotes, no surprise given the enhanced velocity coming out of the WSM case. For long-range, flat-country and mountain shooting, the new .270 “Short Magnum” is going to be an extremely versatile cartridge, in all its loadings.

The 7mm WSM performed pretty darned good, too. Its accuracy was exceptional, with Winchester’s Mike Jordan posting 5/8-inch groups at 100 yards with the 140-grain Ballistic Silvertip load while sighting-in (Mike had to hunt with the 7mm WSM because the rest of us insisted on having the .270). When Winchester Ammunition, Browning, and USRAC introduced the .300 Winchester Short Magnum in 2000, they termed it a “New Shape in Magnum Cartridges” and promised more to come in an ongoing family of WSM loads. The immediate question, asked even in the opening paragraphs of the initial reviews of the new .300 WSM, was “What would the next caliber in the WSM family be?” At a 2001 SHOT Show breakfast for writers last January, Winchester took a poll. The overwhelming favorites were, first, the .270 and, second, the 7mm. So for 2002 we’re getting both.

Winchester’s new “Short Magnums” are the first new named cartridges from the company in over a quarter-century. The .300 WSM, .270 WSM, and 7mm WSM truly represent a major paradigm shift in mainstream high-power rifle ammunition development. In fundamental performance terms, their basic design parameters frankly render most existing long-action cartridges obsolete, even the most popular ones, and offer advantages we couldn’t even dream of before the industry-wide improvements in propellant technology, bullet design, and manufacturing precision of the last dozen years. Other major ammunition and rifle manufacturers are already following the lead of Winchester, Browning, and USRAC down this road with short-form cartridges and rifle developments of their own.

This is only the beginning.

  • michael a pittslet

    The 270WSM is the best round I have ever fired! That is not just my opinion alot of fact behind me to back my statment up. At hunting camp it is said let the buck pole do the talking and for the last few years it has done just that if you don't own one you should because once you take this tac driver hunting you won't want or need to take anything else.

  • Jeff Nelson

    I seriously doubt that J. O'C would have had anything positive to say about the .270 WSM. Jack didn't particularly care for small-bore magnums, and the .270 WSM dosn't do anything that the .270 Winchester (or .270 WBY) can't do equally as well.

    • Patrick

      Jack made the longest shot ever with .270 at 3060ft look it up he loved the .270

  • Tom Carvelli Sr.

    Recoil is not bad at all with a Kimber 8400.
    Blast is a little annoying but not bad.
    Accuracy is excellent….1/2 inch 3 shot groups are not unusual.
    I have tried several different powders R22, H4350, VARGET, IMR4350, R19 and others.
    R19 is the powder to use……period.
    R22 would be a close second choice.
    ALL of the factory loads are excellent.
    130 gr. Remington,150 Winchester Power Point and Federal 150 gr. Fusion are all good.
    Any loading with Nosler Partitions or Accubond are also excellent.

  • Jack Bennett

    The .270 wsm is the worst round I have ever fired. I bought a Savage model 11 with the accutrigger. I have fired many different brands of factory ammo at different weights. I do reload and bought a set of dies for it. I've reloaded several different weight bullets from different companies. The best shot group I can get at 100 yards is about 4.5 inches. The worst group I get is all over the entire target, if I can hit it at all. I did send the rifle back to Savage and told them the problem. They sent it back to me and said that they are shooting sub MOA with it. I've tried several different scopes with it, taking some scopes off of other rifles that I own that do shoot great and still get the same results with this rifle. I have owned it since I first heard about this new caliber. I've been ready to sell it a few times, but I just keep holding on, wishing that it would somehow start shooting better. I guess it's not going to cure itself. It's going with me to the next gun show. I do have papers from Savage stating that it's shooting sub MOA if anyone wants to buy it. Ha Ha

    • adam shaffer

      lookin to buy one in the tikka that is the first bad post i have read so far and i have red alot in the last three months

    • Patrick

      Should have went with a Winchester model 70 i have taken multiple shots at 300 yards under 1 inch in space

      • kentann

        I have an early Savage Weather Warrior (Accutrigger, no accustock) chambered in the .270 wsm. I was unable to find any factory loads that pattern better than 2-3in. However l've developed loads with Barnes TTSX (110 and 130 grn) than I can shoot 3 shot sub moa groups all day long. I have done the same with the 130 grn CT (ballistic tip). I am having a heck of a time getting a load worked up for the 140 grn Berger VLD-hunting.

    • steve

      jack bennett should learn how to shoot !!!!!

  • Buck Nasty

    "…the 7mm wsm… which stands to the sam relationship as the long action 7mm rem mag." No Dick If you're comparing the 270 wsm to the 270 win, then the 7 and 30 wsms relate to the 280 and 30-06. I can't imagine the BS and posturing that occur during a gun writer hunting trip.

    • steve

      maybe you should tighten all scope mount and stock screws then clean the barrel. you have lost what mind you thought you had. the 270 wsm is very accurate. what an idiot for posting such a comment.steve@ steve ewing20@yahoo.com

      • steve

        tikka t3 with 3-9×50 ziess conquestscope with warne mounts consistently gives 1inch or less @100 yds with federal premium and nosler trophy ammo.270wsm.

  • tigger

    the 270 wsm is the best all around gun i have ever shot all i know is it lets the air out of what ever i point it at
    .

  • larry

    i shoot a left handed tikka. with 140 accubonds it shoot .5 groups at 100 yards. using R-22 powder.

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