Sierra MatchKing X Bullet: Sleek Hollow Point Boat Tail

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Sierra Bullet Co. recently launched a new thin-jacketed, hollow-point hunting bullet. Named the MatchKing X, it is aimed at the demographic of hunter who chooses to use target-type bullets on big game.

Sierra’s Tipped MatchKing—along with similar competing designs from other companies—was already becoming popular among hunters, so one might ask why the company would introduce a non-tipped, target-type hunting bullet.

The answer is that the new MKX is for hunters who want their bullets to penetrate a few inches before expanding violently inside the vitals.

“The reason the MatchKing X was created was to give hunters a bullet capable of match-level accuracy and consistency while also providing exceptional expansion at low impact velocity inherent with long-range shots that this bullet enables capable shooters to be able to make,” said Sierra’s Anne Stuart.

Offerings

Sierra’s new MatchKing X line initially launched with five different versions. There’s a 107-grain 6mm with a G1 ballistic coefficient of .477; a 142-grain 6.5mm with a G1 BC of .595; a 135-grain .277 with a G1 BC of .505; and 175- and 200-grain .308s with respective G1 BCs of .505 and .553.

Sierra says the MatchKing X projectiles have nearly identical profiles and flight characteristics as same-diameter, same-weight standard MatchKings. As a result, shooters may simply substitute MKX bullets into proven handloads worked up for MatchKing bullets.

The MatchKing has a tightly closed hollowpoint that enhances consistency and flight characteristics, but it also makes that tip behave much like an awl because it’s rigid and strong and resists deformation. That’s why hunters using standard Sierra MatchKings sometimes have a bullet pencil right through game without expanding at all, much like a full metal jacket would.

Conversely, the MKX has a slightly larger hollow-point that makes the nose weaker and more prone to deformation, which leads to jacket rupture and dramatic expansion.

Tolerances

I received samples of all the MKXs except the 6mm, and the bullets exhibit some variation in the length of the jacket. This is relatively common in thin-jacketed target bullets, and it’s not something that should put you off the MKX. Like the MatchKing, it should be an accurate bullet that’s easy to get good results with.

I sectioned one of the 142-grain 6.5mm MKXs on my grinder, and as I suspected, the jacket is uniform in thickness all the way from the nose to the base. That contrasts with traditional hunting bullets designed to create a mushroom shape. They have jackets that are very thin at the nose, then gradually become thicker toward the rear. This thickening arrests expansion once it’s progressed to a certain point, ensuring deep penetration.

As best I can measure it, the jacket on the MKX is about 0.0020 inch in thickness all the way back. Clearly, the projectile is designed to rupture on impact. The photo on the next page shows a sectioned MKX alongside a sectioned Berger VLD Hunting bullet—the type of bullet against which the MKX was designed to compete.

Also shown are the Hornady ELD-X bullet, which has a gradually tapered jacket designed for mildly controlled expansion, and a Swift Scirocco II bullet, which has a very thick bonded jacket. This comparison clearly shows the different approaches makers take in terms of jacket design.

Accuracy

To try out the new bullet, I built some handloads with the 142-grain 6.5mm MKX for a 6.5x55 built by Saft Custom Guns. I loaded MKX bullets over Alliant’s Reloder 16, a propellant I’ve had good luck achieving excellent velocities with in various 6.5x55 rifles. It produced exactly 2,800 fps in the 22-inch barrel. Standard deviation was just nine fps.

Accuracy right out of the gate was impressive, even though my prone shooting spot was under construction and I had to shoot off a rickety folding table. With no load workup at all, my first five shots clustered into a 0.79-inch group. That’s darned good for a hunting rifle weighing less than six pounds. I have no doubt that with a bit of load tuning in terms of charge weight and bullet seating depth—let alone a stable shooting position—the 142-grain MKXs will produce half-m.o.a. accuracy.

Because all hunting seasons had ended, I had no way to test the MKX’s on big game. Sierra has always done its homework, and I suspect these new match-accurate hunting bullets will provide spectacular kills on big game. I’d use them on deer up to perhaps caribou-size animals but not on really big-bodied, heavy-boned game, where I prefer a traditional deep-penetrating bullet.

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