But getting the bullet there is only half the equation. There are two trade-offs in bullet design that must be balanced over a wide range of anticipated impact velocities: expansion and penetration. Generally, the more a bullet opens up, the more damage it does. But if expansion occurs too rapidly, the bullet can fail to penetrate deeply enough to reach vital organs. To get the best balance of the two, Winchester designed the XP3 to have what it calls Two-Stage Expansion. The first stage has to do with the opening of the tip into a four-petal X-shape, while the second is the compression of the core and jacket into a "bulge" where the core and jacket meet, meaning the bullet continues to push through, disrupting tissue, while the X-shaped petals cut through it at the same time. This bulge is a common sight on mechanically locked bullets, such as the Swift A-Frame and today's bonded bullets, too.

The XP3's hollow-point cavity is under the tip, and it has X-shaped petals specifically engineered to open up into four separate, partitioned petals that peel back under impact – just like the Fail Safe. "Notching is done early on in the manufacturing process to give the fault lines symmetrical upset for deep, straight penetration," according to Mike Stack, Winchester's centerfire rifle new product development engineer. Also like the Fail Safe, the jacket material is a copper alloy with some zinc added to it. The XP3's top half is copper alloy, while the jacket extends to the base with the lead core exposed on the heel. The lead core adds weight to the rear of the bullet, and it is bonded to the jacket. Under impact, that bonding prevents the lead from fully expanding, and the core and jacket are compressed together, forming the bulge at the center of the bullet.

The overall length of the .308, 180-gr. bullet is 1.371 inches, with 0.164 inches of that being the tip. The jacket material from the beginning of the hollow-point to the top of the lead core measures 0.617 inches. The lead core is thinner at its front to help prevent it from moving forward under impact. In the .308, 180-gr., the core measures 0.232 inches at its thickest but tapers 0.220 inches at its top.

A typical sample bullet fired into 20-percent ballistic gelatin at between 2,800 and 2,900 f.p.s. tells the story of what's happening inside the bullet. The recovered bullet's weight is 177 grs., its height shrank to 0.680 inches, and its outside diameter at its widest point is 0.618 inches. Inside, the front jacket material has been pushed to a height of 0.223 inches, while the core has expanded from 0.220 inches at the top to 0.356 inches at its widest, almost T-shaped, point. The exterior measurement at the "bulge" went from .308 inches to 0.428 inches. The core has also moved slightly forward from the base of the heel upon compression from the impact. In Winchester's tests, weight retention has ranged from 84 percent up to 99 percent, with higher velocity impacts in the 3,200 f.p.s. range being on the lower side and impacts in the 2,800 f.p.s.-range and lower giving the higher numbers.

Through high-speed photography, you can clearly see that the 180-gr., .308 XP3 opens to its full diameter (about 0.625 inches) within the first inch or so of impact, creating both a large temporary wound cavity that later contracts and a permanent wound cavity. What is impressive is its penetration of typically 19 to 23 inches in 20-percent ballistic gelatin at velocities ranging from the muzzle out to a simulated 400 yards. In direct comparison to 180-gr. Power Point WSM loads, the temporary wound cavity is larger with the Power Points, but penetration is about 50 percent greater with the XP3. These are "great long-range bullets and great close-up bullets," said Stack. "There aren't a whole lot of bullets that offer this range of performance. This bullet will open consistently from 3,200 f.p.s. down to 1,600 or 1,700 f.p.s.."

As to its terminal performance on game, I simply don't know firsthand yet, as the trip I sighted-in my New Ultra Light Arms for was cancelled and I ended up with nothing more than a nice target on my refrigerator. Nonetheless, my friend and colleague, American Hunter Editor-In-Chief Scott Olmsted, was in on one of the first hunts with the XP3.

"When we started looking to upgrade the Fail Safe and trying to right the wrongs that were there," said Stack, "we were trying to come up with a bullet that walloped deer, but would perform well all the way up to elk." From what I've seen and heard, Winchester's succeeded in meeting or beating that goal. And, I am confident that, in time, another bullet will join those on which guides and professional hunters confer their highest praise. The XP3 is a "good bullet."

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