The HSM Game King 300 Remington Ultra Magnum (300 RUM) 150 gr Sierra GameKing Spitzer Boat Tail – 20 Rounds Per Box (300RUM11N, UPC 810742023140) is a high-velocity, flat-shooting hunting load engineered for hunters who want maximum reach, accuracy, and terminal performance from their 300 RUM rifles. Built around the legendary 150-grain Sierra GameKing Spitzer Boat Tail (SBT) bullet, this cartridge is ideal for long-range deer, antelope, and similar game where flat trajectory and explosive on-target performance are essential.
High-Velocity 300 RUM Performance with a 150-Grain GameKing
The 300 Remington Ultra Magnum is known for extreme velocity and long-range capabilities. When paired with a lighter 150-grain projectile like the Sierra GameKing SBT, you get:
Blistering muzzle velocities (when fired from standard 300 RUM hunting barrels, per typical 150 gr 300 RUM load data).
Laser-flat trajectories at hunting distances, reducing holdover and simplifying long-range shots.
Ideal performance for medium-sized game where rapid energy transfer and expansion are desired.
This HSM Game King load turns the 300 RUM into a long-distance, point-and-shoot powerhouse for open-country hunts.
Sierra GameKing 150 gr Spitzer Boat Tail – Proven Hunting Bullet
At the core of this load is the Sierra GameKing 150-grain Spitzer Boat Tail—a bullet trusted by hunters around the world.
Key bullet benefits:
Spitzer (pointed) shape for a high ballistic coefficient and minimal drag over distance.
Boat tail base improves downrange stability and helps maintain velocity and energy.
Designed for controlled expansion and effective penetration on deer-sized and similar game animals when shots are placed correctly.
The GameKing line is known for combining match-like accuracy with reliable terminal performance, making it a natural fit for precision-oriented hunters who stretch the distance.
Ideal for Open Country, Western & Long-Range Hunting
This HSM Game King 300 RUM 150 gr load is tailor-made for:
Western big-game hunts where shots often occur across canyons, ridges, and wide-open valleys.
Pronghorn antelope, mule deer, and whitetail in open fields, plains, and agricultural country.
Situations where a light-for-caliber, high-speed bullet delivers flatter trajectory and rapid, effective expansion.
When properly zeroed and matched to your rifle, this load gives you the ballistic edge you need for confidently taking ethical shots at extended ranges.
HSM Quality – Precision-Loaded Hunting Ammunition
HSM (Hunting Shack Munitions) has a strong reputation for producing accurate, consistent ammunition tailored to hunters and precision shooters. In the Game King series, HSM:
Uses premium Sierra bullets for top-tier accuracy potential.
Pairs them with carefully selected powder charges for consistent velocity and point-of-impact.
Loads in quality brass cases, suitable for shooters who may choose to reload after firing.
This focus on uniformity helps minimize vertical stringing and group size—exactly what hunters need when they dial or hold for distance.
Light-for-Caliber 150-Grain Bullet – Flat Trajectory & Reduced Recoil
Compared to heavier 300 RUM bullets (like 180–200 gr), the 150 gr GameKing:
Produces a flatter trajectory, especially inside typical big-game hunting distances.
Offers a slightly softer recoil impulse, helping some shooters maintain better control and faster follow-up capability.
Still delivers immense energy thanks to the 300 RUM’s case capacity and powder charge.
It’s a smart choice for those who want long-range capability with a balance of recoil, speed, and terminal performance on medium game.
Perfect for Zeroing, Practice & the Hunt
When you choose a hunting load, consistency between practice and field use is key. With HSM Game King 300 RUM 150 gr SBT, you can:
Zero your rifle and verify dope using the exact ammunition you’ll carry into the field.
Run realistic practice drills, including prone, sitting, and supported field positions.
Hunt confidently knowing your point-of-impact and ballistic performance have been proven at the range.
Sticking with the same load from sight-in through the hunt maximizes your odds of clean, ethical kills.
20 Rounds Per Box / 20 Boxes Per Case
This ammunition is packaged 20 rounds per box, a standard quantity for premium hunting loads. The designation “20 Per Box / 20 Case” means:
For the individual hunter, a few 20-round boxes provide plenty of ammo to zero, confirm, and hunt with the same consistent load.
Key Features & Specifications – HSM Game King 300 RUM 150 gr SBT
Brand: HSM (Hunting Shack Munitions)
Series: Game King
Caliber: 300 Remington Ultra Magnum (300 RUM)
Bullet Weight: 150 grains
Bullet Type: Sierra GameKing Spitzer Boat Tail (SBT) – premium hunting bullet
Case Type: Brass
Intended Use: Medium-to-large game hunting – ideal for deer, antelope, and similar game at extended ranges, when used within ethical and practiced distances
Packaging: 20 rounds per box, commonly listed as 20 Per Box / 20 Case
Manufacturer Part Number (MPN): 300RUM11N
UPC: 810742023140
If you’re looking for a flat-shooting, accurate, and hard-hitting hunting load that maximizes the long-range potential of the 300 Remington Ultra Magnum, the HSM Game King 300 RUM 150 gr Sierra GameKing Spitzer Boat Tail (300RUM11N, UPC 810742023140) is an outstanding choice—combining Sierra’s trusted GameKing bullet design with HSM’s precision loading for serious performance in the field.
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