The HSM Game King 300 RUM 180 gr Sierra GameKing Spitzer Boat Tail – 20 Rounds Per Box (300RUM13N, UPC 810742023164) is a premium, long-range hunting load built for shooters who want serious reach, power, and precision from their .300 Remington Ultra Magnum rifles. Featuring the proven 180-grain Sierra GameKing Spitzer Boat Tail (SBT) bullet seated in quality brass cases, this HSM Game King ammo is tailored for demanding big-game hunts where consistent accuracy and dependable terminal performance at extended ranges truly matter. winchesterarm.com+1
300 Remington Ultra Magnum Power with a 180-Grain GameKing
The 300 RUM is one of the hardest-hitting, flattest-shooting .30-caliber magnums available, and the 180-grain weight class is a sweet spot for all-around big-game performance. In this HSM Game King load, that combination gives you:
Magnum-level muzzle energy and velocity, ideal for reaching across canyons, cutovers, and open prairie. hsmammunition.com+1
A balanced bullet weight that offers both deep penetration and strong downrange energy retention.
Excellent performance on larger-bodied game like elk, mule deer, and black bear when shots are placed correctly and within ethical distances.
If you’re looking for a true all-around big-game load for your 300 RUM, a 180-grain bullet is a proven choice—and HSM builds this one specifically for serious hunters.
Sierra GameKing Spitzer Boat Tail – Time-Tested Hunting Bullet
At the core of this cartridge is the Sierra GameKing Spitzer Boat Tail—one of the most respected hunting bullets in the industry.
Key benefits of the 180 gr GameKing SBT design include:
Spitzer (pointed) nose profile that improves ballistic coefficient, helping the bullet buck wind and retain velocity over long distances.
Boat tail base that reduces drag and enhances stability, supporting tight groups and flatter trajectories. hsmammunition.com+1
A jacket and core design created for controlled expansion and reliable penetration on medium to large game animals.
Sierra’s GameKing line has earned a decades-long reputation for combining match-like accuracy with reliable on-game performance, making it a perfect match for HSM’s premium hunting ammo.
HSM Game King Series – Components Tuned for Accuracy
The HSM Game King series is built around a simple idea: pair time-honored Sierra GameKing/Pro-Hunter bullets with precisely matched components for each caliber to maximize accuracy and performance. hsmammunition.com+1
For the 300RUM13N load, that means:
Carefully selected powder charges tuned to the 180-grain GameKing for consistent velocities shot-to-shot. Georgia Guns & Ammo+1
High-quality brass cases that feed and extract smoothly in bolt-action hunting rifles and offer the potential for reloading. winchesterarm.com+1
Production standards aimed at delivering the kind of repeatable accuracy long-range hunters demand.
HSM’s Game King lineup is so precisely matched to each bullet that many shooters describe it as having a “handload feel” straight out of a factory box. hsmammunition.com
Long-Range Capable – Flat Trajectory & Strong Downrange Energy
With the 300 RUM’s large case capacity driving the 180-grain GameKing SBT, this load is tailor-made for long-range big-game hunting:
The combination of high velocity and aerodynamic bullet shape delivers a flat trajectory that simplifies holdovers. ammohero.com+1
The 180-grain bullet retains substantial downrange energy, helping ensure effective performance at extended but responsible distances.
Ideal for Hunters who glass and shoot across wide-open terrain, such as Western mountains, badlands, or large agricultural fields.
When paired with a properly zeroed scope and a solid ballistic dope card, this HSM Game King 300 RUM load provides the confidence you need when that once-a-season shot presents itself out past typical woods ranges.
Brass-Cased, Centerfire Rifle Ammunition – Built for Reliability
This HSM Game King 300 RUM 180 gr load is built on quality brass cases with standard centerfire primers: winchesterarm.com+1
Brass promotes reliable feeding and extraction, even in harsh conditions.
Boxer-primed brass is widely favored by reloaders, giving you the option to reuse cases after the hunt.
Each round is assembled to function as a dependable hunting cartridge, not budget plinking ammo.
From sight-in sessions to the final shot of the season, this ammo is designed to function shot after shot.
Ideal Use Cases – Elk, Mule Deer, and Big-Game Hunts
The HSM Game King 300 RUM 180 gr SBT is an excellent choice for:
Elk and mule deer in open Western terrain where shots may be long and quartering.
Black bear or similar big game, where you want a strong combination of penetration and expansion.
Hunters who demand a single, do-it-all 300 RUM hunting load that can handle a variety of conditions and animals.
As always, shot placement and staying within your practiced, ethical range are critical—but with this load, you have a cartridge built to support serious big-game work.
20 Rounds Per Box / 20 Boxes Per Case
Packaging is straightforward and hunter-friendly:
Each retail box contains 20 rounds of HSM Game King 300 RUM 180 gr ammunition. winchesterarm.com+1
A full factory case includes 20 boxes (400 rounds total), a note often reflected in the “20 Per Box / 20 Case” description used by distributors and retailers. winchesterarm.com+1
For the individual hunter, one or two boxes typically cover:
Zeroing and confirming your rifle’s point of impact.
A realistic amount of practice from field positions.
Enough remaining rounds for the hunt itself.
Key Features & Specifications – HSM Game King 300 RUM 180 gr Sierra GameKing SBT
If you want a hard-hitting, long-range hunting load that takes full advantage of the 300 Remington Ultra Magnum while leveraging the proven performance of the 180 gr Sierra GameKing Spitzer Boat Tail, the HSM Game King 300 RUM 180 gr SBT (300RUM13N, UPC 810742023164) is a standout choice—offering precision, power, and confidence for your next big-game hunt.
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