.223 Winchester Super Short Magnum

Even through the 14x magnification of the RamTac scope, the prairie dogs were so far away they looked like mice. The crosshairs settled with some daylight showing above one of the rodents. A puff of dust marked the bullet high. My mind was still tuned into the .223 Remington I had been shooting and refused to lower my aim. The following two bullets also went high. Finally I had a seriou­­s discussion with myself and aimed right on. The dog went pop.

I caught the .223 Winchester Super Short Magnum (WSSM) case as it ejected from the Cooper rifle. It had the heft of a silver dollar and sparkled in the prairie sun. I have got to buy a rifle for this cartridge, I told myself.

History of Fast .22s

The .223 WSSM is the most recent in a line of cartridges firing .22-caliber bullets at high speed. Win- chester started the line in 1935 with the .220 Swift. You know the story of the once king of varmint cartridges – gossip of torched rifling and erratic pressures and yet a loyal, although small, following. The Swift nearly died, but now it’s back, at least somewhat. The .22-250 appeared about the same time as the Swift, and its popularity was steady through the years, even though it was not a commercial cartridge. The .22-250’s status changed in 1964 when Browning chambered it in its short bolt-action rifles based on a Sako action. Not until a year later, though, did Remington give the .22-250 a home in its cartridge lineup. That took away the little interest in the .225 Winchester that was introduced in 1964 to replace the Swift.

It’s funny how the .22-250 was and is everyone’s darling. Although it burns only a few grains less powder than the Swift, you don’t hear complaints about burning barrels or misbehaving pressures with it. That’s been the status of top velocity .22 cartridges over the last 40 years, until the new .223 WSSM.

The Case for the .223 WSSM

The popularity of the .223 WSSM will depend on developing the same good name as the .22-250. From extensive shooting in the field and at the bench, this new .22 can do that. It produced impressive bullet speeds matched by no other established .22-caliber centerfire, along with excellent accuracy, flat trajectories and easy reloading.

When Winchester Ammunition engineers started developing the .223 WSSM, they wanted only a slight increase in bullet velocity over the .22-250 and the Swift – mainly, I believe, for marketing. Because as everyone knows, speed sells. A cartridge that produced bullet speeds much faster than the Swift, though, could lead to talk of an accelerated rate of bore erosion, weird pressures and such – just like what has plagued the Swift for years. The new .223 WSSM beats the .22-250’s velocity by nearly 300 fps in factory loads and about 200 fps in handloads.

When Winchester’s .300 WSM case came along, it was the perfect vehicle for the new .22. The case was cut off to a length of 1.67 inches and necked down to .22 caliber. That’s about .25 inch shorter than the .22-250 Remington case.

This short case also fits on a shorter, short bolt action. Everything else considered, the shorter the action, the stiffer the action and the better the accuracy. To accommodate the new cartridge, Browning and Winchester firearms have made new A-Bolt and Model 70 bolt actions that measure .5 inch shorter than their regular short actions.

The .223 short also has less body taper than the .22-250 and Swift. That is supposed to reduce case stretching during firing and resizing. For sure, the aggravating rim on the Swift case is a relic of the past.

The Super Short Magnum case has a very thick web, walls and neck. Its neck rim diameter measures .022 inch, compared to .015 inch for the .22-250 Remington.

In fact, the short magnum case weighs 60 percent more than a .22-250 case. As near as I can weigh, a fired .223 short case holds 54.8 grains of water, compared to 46.5 grains in a Swift case and 45.0 grains for the .22-250.

When the .223 Winchester was being developed, there was considerable discussion about bullet weights and rifling twist. A few shooters wanted a cartridge to shoot relatively heavy 80-grain, .22-caliber bullets. To stabilize those long bullets requires a rifling twist of about one turn in 8 inches. That fast twist together with the .223 Winchester’s fast bullet speed would tear apart most lighter bullets. “We did not concern ourselves with the 70-plus weight bullets,” said Glen Weeks, an engineer for Winchester Ammunition. “We feel that this is a very small segment of the shooters, and anyhow, those guys will buy custom guns and handload.” Weeks said he did design the .223’s chamber to accept an 80-grain boat-tail. “However, I think such a long bullet will have a fair amount of intrusion into the case,” he said.

“A one in nine or faster twist (in the .223 WSSM) probably would not spin apart the premium lightweight bullets such as a Ballistic Silvertip,” Weeks said, “but it definitely would our 45-grain jacketed hollowpoint.” To hedge their bets a bit, Winchester Ammunition and Browning/Winchester Firearms established the rifling twist for the .223 short at one in 10 inches.

In the Field

So far, I’ve taken the .223 WSSM on three trips for ground squirrels and prairie dogs and one outing to Texas for deer, hogs and javelina. The South Texas trip was last January. I hunted with a Browning A-Bolt with a 21-inch barrel and a Cabela’s Pine Ridge 3-9x-40 scope. The whole outfit weighed slightly over 7 pounds. The load was Winchester’s Super-X 64-grain Power-Point bullet. Three-shot groups ran just a smidgen over one inch at 100 yards from the light rifle. Winchester clocked this bullet at 3,600 fps. From the 24-inch barrel of a Cooper Arms rifle, the 64-grain bullets reached 3,635 fps and 3,784 fps from the 27-inch barrel of a Sisk rifle based on a Remington Model 700 action.

Speaking of a light and handy rifle, the Browning A-Bolt weaved easily through mesquite thickets. I hardly knew the rifle hung from my shoulder, until it was time to use it.

The first evening my guide and I played cat-and-mouse with several bucks, as they slipped from one patch of brush into another. When we circled downwind, they tiptoed out the other side. Finally, a nine-point stepped into the clear at 50 yards. The 64-grain bullet went through the buck’s lungs and out the far side. It fell right there.

Over the next few days I shot more game from 30 to 60 yards. Three whitetail does and a javelina fell from one shot apiece. The last evening of the hunt I aimed for the brain on a 90-pound hog destined for the barbecue. I pulled the shot, and the bullet hit the base of its nose. The pig oinked loudly and spun around. I fired a second bullet in the center of the twirling pig and luckily hit it in the brain.

The .223 WSSM is far from my first choice as a deer cartridge. But a lot of hunters use .22-caliber cartridges on deer and antelope. Of the 28 animals hit by hunters on the Texas trip, all were recovered. So if you’re going to use a .22, select a good bullet like the 64-grain Winchester, Nosler 60-grain Partition or Barnes X-Bullet and wait for a good broadside shot.

The .223 Winchester’s real niche is varmints like coyotes, marmots and prairie dogs. On two trips for ground squirrels and another for prairie dogs last June, I noticed the magnum’s flatter trajectory made the little rodents slightly easier to hit between 350 and 400 yards than the .22-250.

How’s this for flat shooting? The Winchester Supreme 55-grain Ballistic Silvertip left the barrel of a Cooper Arms Model 22 rifle at an average speed of 3,904 fps. At 100 yards the bullets hit .95 inch above where the crosshairs rested. At 300 yards, the bullets dropped 1.85 inches below aim (and grouped three bullets in 2.28 inches) and 9.5 inches low at 400 yards. The slightly less streamlined Barnes 50-grain Varminator at 3,934 fps hit 1.5 inches high at 100 yards, dropped 3.5 inches at 300 yards (and grouped four bullets in 1.09 inches) and 12 inches low at 400 yards.

In contrast, most factory .22-250 Remington loads with 55-grain bullets I have clocked fly about 3,650 fps at the muzzle. Those loads have about one inch more drop at 300 yards and 3 inches more drop at 400 yards than the .223 WSSM.

That added performance comes at the expense of burning 4 to 8 grains more of the same powders used in the .22-250. Fire that much powder through a .22-caliber bore 300 or more times at prairie dogs during a day and after a few days the throat of a barrel bore will start to resemble a sewer pipe. For a .223 WSSM barrel to last, it should be restricted to a slower pace of shooting.

I compared a cast of the chamber and first few inches of the bore of a new Cooper Arms Model 22 .223 WSSM with a cast made after the rifle had been fired between 500 and 700 rounds. Most of the cartridges had been fired pretty much one right after another. Comparing the two casts, I couldn’t see any signs of wear on the lands. However, a Hawkeye borescope did reveal an ever so slight amount of gas cutting at the beginning of the throat. Browning firearms engineers said they started to notice  rifling wear in their A-Bolt rifles after 1,500 rounds. Those rifles had been shot hard and fast on prairie dog shoots.

Handloading

I used once-fired Winchester plain brass and nickel-plated cases to reload the .223 WSSM and Redding reloading dies to size the cases and seat bullets. The Redding seating die precisely aligned all bullets from 40 to 69 grains in the case necks with only about .001 inch of misalignment measured on an RCBS Case Master Gauging Tool. All the bullets were seated .03 inch from contacting the beginning of the rifling.

The .223 WSSM was very ac­curate. The Cooper Model 22 rifle wore a Swarovski 6-24x scope and the Sisk rifle a Nikon 5.5-16.5x    Titanium scope, both in Talley bases and rings. Anytime I con­sistently shoot groups under .5 inch, I know the proper gear has more than compensated for my wiggles and wobbles. Only the Barnes X-Bullets and Nosler Partition bullets grouped over one inch in the Cooper and Sisk rifles. Only four loads with the other bullets grouped over one inch in the Cooper rifle. None of the other bullets grouped over .96 inch in the Sisk rifle.

Rob Bear of Cooper Arms said he is very impressed with the .223 magnum’s accuracy. “We’re shooting groups of a third- to a quarter-inch with our rifles chambered in .223 magnum,” he said. “In comparison, our rifles chambered in .22-250 group more like half an inch.”

The only quirk that arose shooting the .223 WSSM reloads was the failure of two powders with the Nosler 40-grain Ballistic Tip to expand cases enough to completely seal the chamber of the Cooper rifle. The cases from those loads came out of the chamber coated in black-powder residue. The powders were Hodgdon’s Varget and Ramshot’s Big Game. Hodgdon lists the Varget load I used, 43.5 grains, as maximum. So there’s no going to an increased amount of powder to fix the problem, which did not appear in the Sisk rifle. Perhaps its slightly tighter chamber than the Cooper rifle was the reason. The problem also failed to appear in the Sisk rifle when I fired 36.0 grains of Varget, which is a minimum load, with the Sierra 55-grain BlitzKing.

The mornings were calm when I shot the Cooper rifle at paper targets at 100 yards. The accuracy listed in the table is pretty much what I’m capable of shooting in the Cooper rifle with my handloads and factory rounds.

The wind gusted and the dirt blew the days I shot the Sisk rifle. However, the wind never moved the rifle. At 17 pounds, 5 ounces, it should have been steady on a rest. The majority of that weight came from a Shilen match-grade stainless steel barrel that Charlie Sisk left at 27 inches and 1.35 inches in diameter. Sisk cut the .223 magnum’s chamber with a reamer made by Dave Kiff of Pacific Tool and Gauge (PO Box 2549, White City OR 97503). “I think a slightly tighter chamber than those on factory rifles adds a lot to accuracy,” Sisk says. “Dave Kiff and I go back and forth quite a few times before he finally comes up with the dimensions of a reamer I want.” The barrel was threaded to a Remington Model 700 short action and set in a Brown Precision Benchrest stock.

I shot the rifle one round after another, and the barrel became so hot the Nikon scope grew warm. But bullet impact remained the same, and groups remained nice and round with no sign of walking.

The chamber in the Sisk rifle was a bit tighter than the chamber of the Cooper rifle. As a result velocities (mainly because of the 27-inch barrel) and pressures were higher than in the Cooper rifle, and a couple of loads that worked fine in the Cooper rifle were too hot for the Sisk rifle. But of course, you will reduce the loads listed in the table by 3.0 grains to start.

Speaking of barrel length and velocity: The following velocities are what Glen Weeks of Winchester Ammunition recorded with the .223 magnum shooting Winchester 55-grain Ballistic Silvertip loads starting with a 30-inch barrel then cutting off one inch of length at a time down to 18 inches:

  barrel
  length    velocity
 (inches)    (fps)

    30         3,991

    29         3,968

    28         3,950

    27         3,947

    26         3,913

    25         3,898

    24         3,855

    23         3,847

    22         3,789

    21         3,736

    20         3,688

    19         3,711

    18         3,657

Recommending a certain bullet and powder for the .223 magnum is difficult when so many combinations shot so well in the Cooper and Sisk rifles. Actually, if you’re not a handloader, the Winchester Supreme 55-grain Ballistic Silvertip load is difficult to improve upon.

Only one problem arose while reloading the Winchester cases. I commonly stick a bullet in the neck of a fired case to make sure it has expanded enough to safely release the bullet on firing. Bullets easily slipped all the way into the necks of the plain brass cases, but with nearly all the nickel-plated cases, the bases of the bullets inserted in the necks stopped at the junction of the neck and shoulder. I finally had to grind off half of the neck and shoulder from a case to see the obstruction with a magnifying glass. Inside the neck at the junction of the shoulder and neck were folds and ridges in the brass. The ridges protruded enough into the neck of a fired case to keep a bullet from fully entering the neck.

These folds are formed by all the swaging required to neck the large diameter short magnum case down to hold a .22-caliber bullet. The folds are often visible on the outside of cases at the junction of the shoulder and neck. Glen Weeks said the extreme reduction of the case to form the neck is why the .223 WSSM has a 28-degree shoulder angle instead of the 35 de­grees of its parent cartridge, the .300 Winchester Short Magnum.

“It would have been darn near impossible to reduce a 35-degree (shoulder) to that small of a hole,” he said.

The problem was easily fixed. The sizing button in the resizing die ironed out the ridges when it was pulled back through the necks. However, a hard push on the reloading press handle was required to pull the sizing button back through the neck, even when the inside of the necks had been lubricated. The ridges disappeared in the necks the third time they were resized.

Winchester Ammunition made a good decision with its choice of a one-in-10-inch twist for its new .223. That twist stabilizes bullets from 40 to 70 grains. Those weights cover about all the shooting you need with a .22 centerfire. Even the one-in-12-inch twist in the Cooper rifle I shot stabilized 40- to 69-grain bullets. (To tell the truth, if I need a heavier bullet than 69 grains, I’ll trade up to a .25-06.) I shot a couple of groups at 40 yards with the Sierra 69-grain hollowpoint boat-tail (HPBT) Match bullets to determine if these long bullets required some additional distance to fly straightly. Groups were one hole. About all this proves is bullets aligned straightly in the case and the chamber throat fly straightly the moment they leave the muzzle. The one-in-14-inch twist of the Sisk rifle, though, failed to stabilize the 69-grain Sierras.

Speaking of efficiency – one of the short and super short magnums’ claims to fame is their short and wide powder column promotes an especially efficient and consistent powder burn. I’ll go along with that, somewhat. Looking over my chronograph records, I noticed the .223 magnum and the .22-6mm cartridges shoot nearly identical amounts of powder and return approximately the same bullet speed. However, the .22-6mm has a comparatively long and thin powder column. Yet the energy delivered to the energy supplied by the .22-6mm is exactly the same as the .223 WSM. The powder weights and resulting speeds of the same kinds of bullets for the two cartridges, both shot through 24-inch barrels, are shown in Table I.

Competition

The new .223 WSSM’s competitors are the .223 and .22-250 Remingtons and the .220 Swift.

This new .22 will never approach the .223’s popularity. The .223 Rem- ington is chambered in a vast variety of rifles. Factory cartridges and handloads in the little .223 are economical to shoot; brass is as cheap as rocks on the ground. It’s also easy on barrels, even shooting 500 rounds a day at varmints. For the investment of slightly less than 30 grains of powder, the .223 Remington shoots flat enough and carries enough bullet energy to cover about 90 percent of varmint shooting. It’s also a fun cartridge for practice.

The other 10 percent of the time, when a coyote looks back at 375 yards, is why hunters choose the .22-250, Swift and now the .223 WSSM. The .223 short does have about a 200 to 250 fps velocity advantage over the .22-250 and Swift in barrels of the same length. The resulting few inches less bullet drop will help wipe the smirk off a rockchuck peaking over a boulder at 400 yards.

How popular the new .223 cartridge will become will depend, for one, on how many different rifles are chambered for it. That’s the big hurdle. Browning and Winchester firearms have gone to the expense of making a new shorter, short action A-Bolt and Model 70. Cooper Arms has also taken that step with its new Model 16. Of course, single shots, like the Ruger No. 1 and Thompson/Center Encore, will readily accept the cartridge. Will it be worth the expense and time for Savage, Ruger and maybe even Remington to make a shorter bolt action to accept only the .223 WSSM and its big brother the .243 WSSM? I don’t count beans, so beats me. All I know is the cartridge fails to feed from the mag­azine of a regular Remington Model 700 short action. Cartridges tend to nose dive and jam when fed from its magazine. A regular short action does make a good single shot by inserting a loading pan in place of the magazine follower.

One issue that must be addressed is barrel wear in the .223 WSSM. If it’s saddled with the Swift’s reputation of consuming rifling like a beaver gnawing aspens, its popularity will be limited. I didn’t see any great amount of wear in the bore of the .223s I fired. Actually, a person who is fortunate enough to have the time and money to burn out a .223 WSSM barrel won’t mind buying a replacement barrel.

When I buy a new .22 centerfire, it will be for the .223 WSSM, for several reasons. The short cartridge fits on a shorter action, the case itself is heck for stout, its little body taper is a much better design than the .22-250’s and Swift’s sloping case bodies. The rifle’s one-in-10-inch twist allows shooting long and pointed bullets up to 70 grains. The extra bullet speed will also come in handy because coyotes bug me when they stand out on a flat plain and I only have a vague idea of the range. Long-range shooting is why I’m buying a .223 Winchester Super Short Magnum.