October 2000

State-Of-The-Art Sabot Slugs: Winchester’s Partition is Golden

Of five commonly available slugs ready to launch in your rifled-barrel shotguns, we thought the new high-speed offering from Winchester/Olin was the top dog.

[IMGCAP(1)] Shotgun hunters are currently blessed with some of the best projectiles—sabot slugs—they’ve ever had to shoot, but improvements in these rounds have been slow in coming. Winchester-Western ballistician Karl Foster redesigned the old pumpkin-ball slug into what is essentially a 20th century .72-caliber Minie Ball in 1933. From that breakthrough until the early 1980s, there was very little change in shotgun slugs—until the advent of rifled barrels for shotguns and sabot slugs changed everything. By encasing an aerodynamic .50-caliber pellet-like projectile in a two-piece plastic sleeve of bore diameter to grip the rifling (an idea used in artillery for nearly a century), slug shooting expanded its horizons significantly.

While sabots were a breakthrough in accuracy and expanded effective range, they still relied on the same nose-heavy design as original slugs for accuracy. You’ve undoubtedly heard slugs compared to badminton shuttlecocks or the “rock in a sock” analogy. The sabots were also very hard, so although they gave hunters greater accuracy and effective range than full-bore slugs, they did not expand well on deer-sized game.

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Remington advanced sabot design another step in 1993 when the company introduced its original Copper Solid. Machined out of solid-copper bar stock, the Copper Solid was the first shotgun projectile that was rear-weighted, like a bullet, rather than nose heavy.

“The industry had been very cautious not to make a slug that looked or acted like a bullet,” said one industry source. “But when the Copper Solid came out and was not banned, it opened the doors for us to use bullet-like slugs, which in turn opened a whole new realm ballistically.”

The original Copper Solid was just as hard as the early sabots; thus, it didn’t solve the hunting problem. To solve the expansion woes, Federal and Remington brought out readily expandable .50-caliber sabot bullets in 1997-98, and Winchester and Hornady went to extreme velocities with new slugs in 2000.

But which one of the current crop of saboted slugs is best for your deer hunting? We decided to test five of the most common brands head to head to see what sabot best combined ballistic performance, accuracy, and downrange effectiveness. They were the Lightfield Hybred Sabot, the Remington Copper Solid, the Federal Barnes eXpander, the Hornady H2K Heavy Mag, and Winchester’s new Partition Gold sabot slug.

The Match-Up
We opted to shoot 12-gauge sabots suitable for use in a rifled barrel, which gave us the most examples and represented more than 80 percent of the sabot slug market. We also kept the test to 2 3/4-inch slugs since they are invariably better performers than their 3-inch counterparts.

The test guns were a 12-gauge RSG-12 Tar-Hunt custom slug gun out of Randy Fritz’s custom shop in Bloomsburg, Pennsylvania, and a SB980 H&R bull-barreled single-shot 12-gauge slug gun. The Tar-Hunt’s 1-in-28-inch rifling twist rate and 20-inch barrel and the H&R’s 1-in-34 twist and 24-inch barrel pretty much covered the variables of commercially built guns.

Setting up a range session to test five brands and types of sabot slugs wasn’t as simple as it sounds. The slugs shed their plastic sabots soon after leaving the muzzle, and the discarded ejecta becomes destructive, erratic-flying wingmates to the slug downrange. To protect our equipment, we built a plywood cage that shielded the chronograph’s three sky screens and four-foot bar.

We cleaned both gun barrels to an absolute shine with Shooter’s Choice MC-7 bore cleaner, a phosphorus bronze brush and patches. Two warming shots were fired, then one shot every minute thereafter. We gripped the guns tightly and drew them solidly to shoulder, leaving the gun forearm to rest on the front bag with no hand grip. In each gun, we fired five slugs of each brand through an Oehler 35P chronograph to determine average muzzle velocities. All muzzle velocities were significantly below the manufacturers’ claims, which were probably achieved in tight 30-inch proof barrels from bolted-down actions machine-fired at indoor ranges. We found only single-digit differences in velocities between the 20-inch and 24-inch barrels, but significant standard deviation in each load.

The .44-caliber Hornady H2K was the velocity leader with a 10-shot average of 1,985 fps, followed by Winchester’s new .50-caliber Partition Gold at 1,960 fps. Both manufacturers claim better than 1,900 fps in factory barrels. But with ballistic coefficients over .200, both slugs offered 400 to 500 fps over standard sabot loads. Both slugs also boast previously unheard-of muzzle-energy measurements around 3,000 foot-pounds (a half-ton advantage over the rest of the market) and retain nearly a full ton of energy at 125 yards. That’s 600 foot-pounds more than the expanding copper slugs.

What does that mean in trajectory? Well, the rule of thumb for a 100-yard zero with typical (1,300 fps) sabot loads was to center them 2 to 2.5 inches high at 50 yards. The new Winchester and Hornady loads need only be 0.7 inches high at 50 to zero at 100. In fact, print them 2 inches high at 50 now and you’ll have a 150-yard zero. That translates to a maximum point-blank range (plus/minus 3 inches from zero, meaning no hold-over) of 178 yards. These are shotgun slugs we’re talking about—with performance that rivals the .45-70 centerfire rifle.

For accuracy, we shot each load with each gun at 50 yards (five five-shot groups) and repeated the process again at 100 yards. With the exception of the Hornady H2K, all of the other slugs showed same-hole accuracy, or close to it, for five-shot groups at 50 yards. The Hornady grouped poorly at 50 yards and threw slugs so poorly at 100 that no group measurement was attainable.

The Winchester Partition Gold grouped extremely well out of both twist rates, the smallest five-shot group at 50 yards being three-quarter inch and the least accurate a hair over an inch. At 100 yards, the Tar-Hunt threw one 1.18-inch five-shot group with the load, and neither gun grouped larger than 2.48 inches.

The hulking 585-grain Lightfield was a surprising second in the accuracy department at 100 yards, with one group of 2.25 inches, despite not being able to get under an inch at 50 yards like the Winchester, Remington, and Federal entries did.

We felt that expansion tests in water proved nothing since virtually anything will mushroom in the unforgiving medium. Wet newspaper was a similar no-go as a penetration medium since the hollow-nosed copper slugs, which mushroom readily on deer, did not expand at all, thus out-penetrating all others as solids.

The actual penetration and expansion tests came from personal experience with each load on deer. We’ve recovered several Federal Barnes eXpanders and Remington Copper Solids from deer carcasses, all of which mushroomed perfectly and retained 100 percent of their weight and mass. We’ve recovered many Lightfields from a variety of game (deer, caribou, black bear, pronghorn, and feral pigs) over the years and all expanded well while retaining about 80 to 85 percent of their mass.

We’ve only been able to recover one example each of the Winchester Partition Gold and Hornady H2K speedsters from deer—both end-to-end shots through the chest that were recovered in the hams. Both slugs mushroomed well and, while most of the soft lead washed out of the hollow nose, both retained 75 to 80 percent of their mass. Here’s what we thought of the loads individually:

Winchester Supreme Partition Gold
Our recommendation: This is the best-performing slug we’ve ever shot at a target or deer.

Not only does the Supreme Partition Gold offer outstanding accuracy, but the .220 BC is unheard-of (Foster slugs are .060). No others can claim 1,800+ fps velocity and huge retained energy with that kind of accuracy.

The slug went into production just one week before the test last summer. But we had an opportunity to hunt the 1999 season with prototypes. None of the eight deer we took with the slug (at ranges from 40 to 120 yards) took another step.

The slug was a three-year development project at Winchester-Olin. The largest problem was building a sabot with sufficient integrity to withstand the huge inertia exerted at setback. Designers solved the problem by molding an aircraft-aluminum disk into the floor of the sabot—an expensive manufacturing step that makes the Partition Gold pricey. It’s a 12-gauge-only slug right now.

Lightfield Hybred Sabot
Our recommendation: We highly recommend this slug as a hunting round, given its inherent accuracy and retained stability and reputation as a expanding slug on deer. First introduced in 1993 based on a design by British artillery designer Tony Kinchen, the Lightfield incorporates the heft and nose diameter of a full-bore slug with the accuracy of a sabot. The New Jersey-based company originally had its slugs loaded at the now-defunct Activ plant in West Virginia. After some inconsistency in manufacture, the company had Fiocchi load the slugs at its plants, in Fiocchi hulls, in Hungary. More problems surfaced, mostly with the Fiocchi components, and the slugs are now loaded over a proprietary Scandinavian powder in French Cheddite hulls with Cheddite primers. Based on limited hunting experience, we also think this is a good performer in 20 gauge. A 3-inch 12-gauge version is on the drawing boards for 2001.

Remington Copper Solid
Our recommendation: This round is an accurate and dependable performer on game. Originally designed in an extremely hard copper-bar format, the Solid caused pressure problems in some guns (Hastings barrels used to be packed with a note that the barrel warranty was void if Copper Solids were used) and was found to be capable of penetrating several layers of Kevlar vests. In 1998 Remington redesigned the slug in a more malleable copper form that expands extremely well and is a veritable ballistic twin to the Federal Barnes eXpander. Also available in 20-gauge and 3-inch 12 gauge.

Federal Barnes Expander
Our recommendation: We found this slug to be interchangeable with the efficient new version of the Remington Copper Solid.

Federal first started loading a readily expandable .50-caliber Barnes MZ bullet in its Premium hulls in 1997, making it the first true sabot (other than the sabot-fullbore hybrid Lightfield) that expanded readily on deer-sized game and actually expended its energy in the animal rather than blowing through. We would not hesitate to hunt deer or close-range bear with the slug, but we hesitate to suggest it for larger game such as caribou. Also available in 20 gauge and 3-inch 12-gauge.

Hornady H2K Heavy Mag
Our recommendation: Pass on this new design. While its velocity was very impressive, the slug was horribly inaccurate.

Accuracy was not acceptable even at short ranges. It’s the only slug on the market that uses a star crimp, enclosing the slug nose. The unpredictable factors of plastic memory, stiffness, uniform pressure on star points, etc., may contribute to the inaccuracy. The bullet-making giant is relatively new to the slug business, however, and we expect an improved load some time in the future. Hornady first entered the market in 1997 with the ATP slug, which was similarly inaccurate and was discontinued in favor of the new H2K Heavy Mag. Not available in other sizes or gauges yet, nor should it be.

Gun Tests Recommends
Winchester Supreme Partition Gold Sabot, $14.39 per box of five. Buy it. It’s the most expensive slug on the market, but is worth the investment if you want the best. The Partition Gold represents the newest wave of slug technology —a high-velocity, controlled-expansion bullet with flat trajectory and tons of retained energy.

Lightfield Hybred Sabot, $7.95 per box of five. Buy it. Much less expensive than the Winchester slug and marginally less than the Remington or Federal performers, the bulky yet accurate Lightfield is a proven performer. With less felt recoil and comparable accuracy to Remington and Federal, the Lightfield offers more knockdown power than any slug other than the Partition Gold.

Remington Copper Solid, $12.98 per box of five. Buy it. A proven performer both in accuracy and effect on deer-size game, although not in the same league with Winchester’s new offering.

Federal Premium Barnes eXpander, $11.95 per box of five. Buy it. A virtual twin to the Remington Copper Solid in all aspects, it’s a truly effective slug on deer-sized game.

Hornady H2K Heavy Mag, $13.25 per box of five. Don’t buy it. During our testing, we saw major problems with accuracy that override superb ballistics that rival Winchester’s.