The .375 Holland & Holland Magnum has been in continuous production since 1912, and that longevity is not accidental. Originally designed to meet the requirements of African professional hunters who needed a single cartridge capable of taking dangerous game, plains game, and everything in between, the .375 H&H has proven itself on every continent against animals ranging from impala to Cape buffalo to brown bear. In North America, it remains one of the best choices for hunters who want a single rifle that handles black bear, elk, and moose with authority — and for the serious handloader, it rewards careful work with outstanding accuracy and terminal performance.
Why Handload the .375 H&H?
Factory ammunition for the .375 H&H is available but expensive — typically $4 to $8 per round for quality loads — and the selection of bullet weights and styles is limited compared to what handloading opens up. Rolling your own .375 H&H lets you tune loads for your specific rifle, select premium projectiles that may not be available in factory form, and manage recoil by backing off to sub-maximum charges when hunting in close quarters like thick coastal Oregon timber.
The .375 H&H also has one of the most forgiving chambers in the centerfire rifle world. Its long, tapered belted case headspaces reliably, feeds smoothly through even cumbersome actions, and the generous freebore typical of .375 chambers gives a wide margin before pressure spikes. It is, in short, a reloader-friendly cartridge.
Brass and Case Prep
Federal, Hornady, Nosler, and Norma all produce .375 H&H brass. For most hunting applications, Federal and Hornady brass delivers excellent consistency at a reasonable price. Norma is the premium choice and worth the investment if you plan to shoot competition or need the absolute best uniformity.
New brass should be full-length sized before the first firing to ensure proper headspace. After the first firing, the case will be fireformed to your chamber and you can switch to neck-sizing only if accuracy is the priority. Hunting ammo, however, benefits from full-length sizing to ensure reliable feeding from the magazine.
Case Prep Steps
- Trim to 2.840 inches (SAAMI maximum is 2.850 inches). Trim after every 2-3 firings.
- Debur and chamfer the case mouth to ensure smooth bullet seating.
- Uniform primer pockets with a reamer for consistency, especially on new brass.
- Anneal case necks every 3-4 firings to maintain consistent neck tension.
Primers
The .375 H&H uses Large Rifle Magnum primers exclusively. The magnum designation matters — standard large rifle primers do not reliably ignite the large powder charges used in this cartridge, particularly in cold weather. CCI 250, Federal 215M, and Remington 9.5M are all proven performers. The Federal 215M is a favorite among precision-oriented handloaders for its consistent ignition and small lot-to-lot variation.
Powders
The .375 H&H case holds approximately 95-100 grains of water and works best with medium-to-slow burning rate powders in the IMR 4350 / H4831 / RL-19 range. Faster powders can generate excessive pressure with the heavy bullet weights this cartridge is designed for.
Top Powder Choices
- IMR 4350: The classic .375 H&H powder. Meters well, temperature-stable, and produces consistent velocity across a wide charge range. Start at 72.0 grains with a 300-grain bullet; max is approximately 76.0 grains.
- H4831SC: Short-cut version of the legendary H4831. Excellent density and metering. Slightly slower than IMR 4350, which can help with heavier 300-grain premium bullets. Start at 74.0 grains; max approximately 78.0 grains with 300-grain bullets.
- Reloader 19: Temperature-sensitive but capable of excellent accuracy in a well-tuned load. Works well in moderate-temperature hunting applications like Oregon fall bear season.
- IMR 4831: Slightly slower than IMR 4350 and well-suited to the heaviest .375 bullets (350-grain solids). Not the top choice for 250-grain deer loads but excellent with heavy projectiles.
Bullets: Matching the Projectile to the Job
The .375 H&H is typically loaded with bullets in three weight categories, each suited to different applications.
250-270 Grain: Deer, Black Bear at Range
The Nosler 260-grain AccuBond and Sierra 250-grain GameKing are excellent choices for open-country hunting where longer shots are possible. At 2,700-2,800 fps, these bullets provide a flat trajectory for the bore and excellent terminal performance on black bear and mule deer. The recoil is noticeably more manageable than with 300-grain loads.
300 Grain: The Standard — Elk, Coastal Bear, Moose
The 300-grain load is the heart of .375 H&H performance. The Federal Trophy Bonded Bear Claw at 300 grains, the Nosler Partition 300-grain, and the Swift A-Frame 300-grain are the top hunting bullet choices. This weight at 2,550-2,600 fps produces devastating terminal performance on heavy game and penetrates deeply even on quartering shots.
For Oregon blacktail and elk in the Coast Range, the 300-grain Nosler Partition has an almost cult following among experienced hunters. It opens reliably at a wide range of velocities, retains weight well, and the dual-core design ensures both expansion and deep penetration.
350-380 Grain: Dangerous Game and Heavy Bear
If you are hunting brown bear or planning an Alaska moose hunt, the 350-grain Woodleigh Weldcore or Hornady DGX Bonded offers maximum penetration and bone-crushing performance. These loads are closer to maximum pressure and produce significant recoil — a good muzzle brake or mercury-filled recoil reducer in the stock makes these loads much more shootable for practice sessions.
Starting Load Data (300-grain Nosler Partition)
- Powder: IMR 4350 | Start: 72.0 gr | Max: 76.0 gr | Velocity: 2,450-2,580 fps
- Powder: H4831SC | Start: 74.0 gr | Max: 78.0 gr | Velocity: 2,450-2,600 fps
- Primer: Federal 215M or CCI 250
- COAL: 3.595 inches (verify against your specific rifle's magazine length)
Always start at minimum charges and work up in 0.5-grain increments. Watch for pressure signs: flattened primers, sticky bolt lift, or cratered primer pockets. Back off immediately if any of these appear.
Oregon Applications
The .375 H&H is heavy medicine for Oregon hunting, but it is not out of place. Coastal Roosevelt elk hunters who work tight timber and want a rifle that drops animals without tracking jobs appreciate the big bore's authority at close range. Black bear hunters using hounds or hunting bait (where legal) in dense timber will find it a confident close-range gun. And for the hunter who hunts both Oregon and Alaska, the .375 H&H is the one rifle that does everything from Cascade deer to Peninsula brown bear.
Handloading lets you tune the experience to your needs. Back the charge down for a reduced-recoil practice load. Tune up to maximum for your heaviest game. The .375 H&H rewards the handloader who takes the time to know it.
