September 26, 2019
Originally pioneered by Barnes Bullets, monometal projectiles accomplish a certain set of tasks that no other type of bullet can. Winchester Ammunition has joined the growing monometal projectile market to offer an addition to the all-copper bullet realm that is interestingly different. Winchester’s bullets were specifically engineered for hunting deer and the like. Named “Deer Season XP Copper Impact,” this monometal features large polymer tips seated in massive hollow-point cavities. They have moderate boattails that enhance aerodynamics.
Critical to hunters pursuing deer in lead-bullet-restricted areas such those in California, Colorado and Illinois, all-copper and copper-alloy bullets are considered non-toxic and legal materials to hunt with.
For hunters that value controlled expansion and deep penetration, monometal bullets maintain weight better than lead-core expanding bullet types, enabling them to drive deeper through heavy bone, dense muscle and vital organs. How? Unless specifically engineered to do so, copper doesn’t tend to fragment or smear off of the expanding bullet’s front like lead does off of the nose of an expanding lead-core bullet. As a result, expanded monometal bullets tend to achieve impressive frontal diameters without suffering much loss of mass. Maintained mass means maintained momentum, and momentum provides penetration.
Momentum is particularly important when taking angled shots on big-bodied game, such as elk and mature black bears. That’s not to say that deep penetration isn’t equally as valuable on deer, but I’ve got a story to tell to support that. More in a bit.
Another advantage of monometal bullets is that they are often forgivingly accurate, and typically more accurate than lead-core bullets in maximum-spec chambers that provide more slop than is ideal. Presumably, this is because they are less likely to deform during acceleration from the cartridge case-mouth to the rifling lead, ending up slightly askew. Monometal bullets are solid, and copper is less malleable than lead, so they tend to self-align in the rifling without much distortion.
My tale about big bucks and the importance of penetration took place almost two years ago as I watched a good friend shoot a mature whitetail buck. We’d stalked through the cottonwood bottoms of Montana’s Powder River to within 80 yards. Scattered patches of late-November snow lay amongst the yellow blanket of leaves, but after the shot reverberated through the woods, the buck leaped, kicked and ran. It didn’t leave a trace of blood — anywhere.
My friend was shooting a very accurate .300 Winchester Magnum rifle loaded with fast-expanding 150-grain lead-core bullets. Impact velocity was likely around 3,100 feet per second (fps) or more, and he’d put his shot into the sweet spot; I watched the impact through my binos.
Unfortunately, the cottonwood copse was full of whitetails and they exploded like quail during the shot. Fresh tracks of running deer littered the ground, meaning that we couldn’t trail the buck. Gridding the area, we slowly and grimly came off the adrenaline high created by the successful stalk and settled in to looking for the buck we knew was surely dead nearby.
Some time later (and almost 200 yards away), I luckily walked onto the deer. It was laying in a slight depression and invisible from more than a few yards. Shot placement had been perfect. The lead-core bullet had expanded violently, turned the entire vital cavity into mush, and the small remainder of the mushroomed .30-caliber bullet was lodged against the hide of the offside. Absolutely perfect performance according to most whitetail deer-killing experts. But every animal is an individual, and that buck had gone a very long way before dropping.
I managed to back-trail the deer for about 40 yards and found one tiny fleck of blood on a snowy patch. Because blood trailing was impossible, had I not begun making wide loops and simply stumbled onto that perfectly shot buck, we may never have found it. Due to that experience (and several others like it), I’ve become a fan of deep-penetrating bullets that usually exit.
Exit holes are almost invariably bigger than entrance holes, and because arteries and fluid systems tend to rupture from the passing bullet, they are pulled with it, leaving somewhat of a directionally-oriented bleed. Exit wounds provide far heavier blood trails than entrance wounds.
Enough talk about forensics. Suffice it to say that Winchester’s new Deer Season XP Copper Impact bullets would have passed through the deer and left a trackable blood trail, that is if the deer hadn’t already fallen dead shortly after impact.
To the Max
Interestingly, the XP Copper Impact bullet is an extension of Winchester’s standard lead-core, polymer-tipped Deer Season XP line. Introduced a few years ago, the original lineup is a very good bullet engineered to provide exactly the type of performance detailed in my story about the whitetail buck. They are light-for-caliber, high-velocity bullets that expand violently, shed secondary-projectile fragments that spiral away from the mushroomed bullet. The XP Copper Impact dumps all of its energy into the deer and comes to rest against the offside hide. Usually, this sort of performance puts a deer down quickly. However, to serve lead-restricted areas and provide discerning hunters who like exit holes with a bit more penetration, Winchester developed the monometal Copper Impact XP as an addition to its popular Deer Season products.
The Copper Impact XP was engineered to provide outstanding, system-annihilating performance on impact, meaning it’s actually designed to shed a bit of weight as the nose mushrooms and peels back. Maximum trauma on deer-sized game shot with an all-copper bullet was the goal, so secondary projectiles (i.e., fragments) are deemed an advantage. Plus, like the original Deer Season XP line, these are in the lighter range, including 150-grain .30-caliber versions; 130-grain .270-caliber versions; and 85-grain .243 versions. This lightness enables maximum-impact velocities at common deer-shooting distances, and maximum energy transfer and expansion on impact resulting in maximum tissue damage. However, bless ’em, XP Copper Impact bullets usually pop out the off-side hide and leave a blood trail. (Not always, as you’ll read about shortly.)
Preparatory to a Colorado field-test hunt for mule deer, I worked 150-grain XP Copper Impact bullets out through two different rifles chambered in .300 Win. Mag. The early production ammo I used for testing had some cartridge case anomalies, so I had to sort out a handful with imperfect crimps. With that accomplished, the ammo provided 11/2-minute-of-angle (MOA) accuracy in the Winchester Model 70 Extreme Weather SS test rifle I had for the hunt. Gratifyingly, it clocked 3,320 fps from the 26-inch barrel. (This is actually more speed than the factory advertises.)
Winchester Model 70 Extreme Weather Specifications
- Type: Bolt action
- Cartridge: .300 Win. Mag. (tested)
- Capacity: 3 rds.
- Barrel: 26 in.; 1:10-in. twist; fluted
- Overall Length: 46.75 in.
- Weight: 7 lbs., 4 oz.
- Stock: Composite
- Length of Pull: 13.75 in.
- Finish: Matte stainless steel
- Trigger: 3 lbs., 15 oz. (tested)
- Sights: None
- MSRP: $1,380
- Manufacturer: Winchester Repeating Arms, 800-333-3288, winchesterguns.com
To evaluate maximum potential accuracy, I fired several groups through a superbly precise custom .300 Win. Mag. rifle fit with a 23-inch Bartlein barrel. The bullet itself proved quite accurate, averaging three-quarter-MOA groups. Muzzle velocity was a bit lower because of the shorter barrel, but still averaged 3,248 fps. That’s plenty.
Because I like hunting with suppressors, I had the muzzle of the Model 70 threaded. Before heading to Colorado, I spun on a SilencerCo Harvester 300 can and re-zeroed the rifle. As I often find, accuracy benefitted a bit, presumably because the weight of the suppressor on the end of the barrel helps dampen oscillation.
My father had suffered a stroke the week before I was heading on assignment, so I opted not to be as picky as I usually would when hunting mule deer. Getting home soon had become a priority. On the third morning of our trip I spotted a mature buck rutting hard on a ridgeline. Stalking across the canyon and up a finger ridge, I plugged in my favorite quick-detach Spartan bipod and went prone in the snow. When the buck chased a doe into view at 170 yards, I put a 150-grain XP Copper Impact bullet into the point of his shoulder, which drove it back toward the quartering-to buck’s rearmost ribs. One giant leap and a short stagger later, he was down. He laid still as the disturbed powder snow sifted silently back down around him.
Being a student of hunting bullets, I performed an informal autopsy before packing the buck off the ridge. The XP Copper Impact bullet expanded immediately and explosively. It broke significant shoulder bone mass, passed through several inches of shoulder muscle, and sheered three ribs as it entered the thoracic cavity. Both lungs were lacerated and one artery at the top of the heart was partially severed, presumably by a fragment. And fragment it did! The bullet mushroomed massively in the deer, shedding significant portions of its peeled-back copper nose.
Due to the acute angle at which I shot the buck, I expected to (and did) find the bullet that had lodged against the hide near the back of the offside ribs. Although much of the front of the nose shredded off, the shank maintained enough mass for deep-driving integrity, and it maintained sufficient frontal diameter to wreak havoc along the way. Averaged, the expanded portion measured .45 inch, almost 11/2 times its original diameter. At its maximum, surely the expanded bullet diameter was shockingly large. As for retained weight, it was precisely 101.3 grains, or about 67 percent of its original mass. Clearly, it was adequate to drive the XP Copper Impact through some 18 inches of muscle, bone and vitals.
Most monometal bullets adhere to the “tough, controlled expansion” mantra, which makes them superbly versatile for a wide spectrum of game ranging up to elk and moose. They almost always provide exit holes, and as a result, excellent blood trails. However, they often don’t kill quite as quickly as a lead-core bullet that expands to create a gigantic wound cavity. It’s an accepted tradeoff, for the most part.
If you like to use just one bullet on various game animals ranging from the diminutive Coues deer to the big, mature elk, a traditional, homogeneous all-copper bullet is fantastic. However, if you’re primarily a deer hunter that likes a bit more penetration than what the common cup-and-core bullets typically provide, Winchester’s new Deer Season XP Copper Impact bullet is a good bet.
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