Rifle · SAAMI
.450 Marlin
Marlin and Hornady deliberately designed it to prevent use in old .45-70 lever actions — a safety feature built into the cartridge itself via a wider belt..
- Caliber
- 0.4583″ · 11.64 mm
- Introduced
- 2000
- Case
- Belted
- Parent
- .458x2" American
- Primary use
- Big Game, Dangerous Game
- Status
- Active
- Introduced
- 2000
- Type
- Rifle
- Origin
- United States
- Inventor
- Marlin / Hornady
- Manufacturer
- Marlin / Hornady
- Standard
- SAAMI
- Status
- Active
- Availability
- Common
- Case capacity
- 74 gr H₂O
- Twist (typical)
- 1:20
- Primer
- Large Rifle
- Case type
- Belted
- Max pressure
- 43,500 psi, SAAMI transducer
- Eff. range
- 200 yd
- Max range
- 2950 yd
- Recoil
- 25–35 ft·lb
Ballistics
Published velocity/energy data isn't available for .450 Marlin. Parent case: .458x2" American.
Performance
Dimensionscase measurements · scale drawing · size vs familiar rounds
Case dimensions — the scale drawing at the top of the page is built from these.
CIP TDCC · approximate| Measure | mm | in | ✓ |
|---|---|---|---|
| Bullet ⌀ | 11.64 | 0.458 | ✓ |
| Neck ⌀ | 12.21 | 0.481 | ✓ |
| Shoulder ⌀ | n/a | ||
| Shoulder angle | n/a | ||
| Base ⌀ | 13.03 | 0.513 | ✓ |
| Rim ⌀ | 13.51 | 0.532 | ~ |
| Belt ⌀ | 13.51 | 0.532 | ✓ |
| Rim thickness | 1.27 | 0.050 | ✓ |
| Neck length | n/a | ||
| Case length | 53.34 | 2.100 | ✓ |
| Overall length | 64.76 | 2.550 | ✓ |
Size vs familiar rounds
Drawn at true 1:1 — every case is accurate relative to the others. Absolute size depends on your screen's pixel density, so measuring one against a real ruler may be off. .450 Marlin is highlighted below.
Factory loads
Being verified
Advertised FPS, energy, and BC are withheld until loads clear verification.
Suitable powders
4 reloading powders listed for .450 Marlin, fastest to slowest. Cross-reference in the finder →
Reloading costestimate cost per round vs factory
Estimate your cost per round and how it compares to factory. Inputs are yours — nothing is stored.
Cost estimate only — not load data. Charge weight is your input; follow published manuals for safe charges.
Firearms chambered in .450 Marlin
Lineage
Connected reference
History
Designed jointly to give lever-action hunters a significantly more powerful option than .45-70. The belt prevents chambering in .45-70 rifles, which couldn't handle the higher pressure. Pairs with Hornady's FTX bullet for dramatically improved lever-action ballistics.
FAQs
- What twist rate does .450 Marlin use?
- .450 Marlin typically uses a 1:20 twist rate.
- What bullet diameter is .450 Marlin?
- .450 Marlin uses a 0.4583″ (11.64 mm) diameter bullet.
- Is .450 Marlin still in production?
- .450 Marlin is active; typical availability is common.
- What is .450 Marlin used for?
- .450 Marlin is primarily used for big game, dangerous game.
- What is .450 Marlin based on?
- .450 Marlin is derived from the .458x2" American case.
- What are the best powders for .450 Marlin?
- Reloading powders commonly listed for .450 Marlin include IMR 4227, Leverevolution, Reloader 7, H322.
Sources & provenance
- Standard SAAMI — ANSI/SAAMI Z299.4-2025 — Centerfire Rifle Velocity & Pressure Data · grain_ballistics, representative_gun archived
- Standard C.I.P. — C.I.P. TDCC — Tables of Dimensions of Cartridges and Chambers
- Standard SAAMI — ANSI/SAAMI Z299 — Cartridge & Chamber Drawings archived
- Manufacturer Hornady — Hornady 2024 Product Catalog (official static.hornady.media PDF) · grain_ballistics, representative_gun archived
- Manufacturer Buffalo Bore — Heavy 450 Marlin Rifle Ammunition — Item 22B (405 gr JFN) · representative_gun, grain_ballistics archived
- Manufacturer Buffalo Bore — Heavy 450 Marlin Rifle Ammunition — Item 22A (430 gr Hard Cast LBT-LFN) · representative_gun, grain_ballistics archived
- Manufacturer Hornady — 450 Marlin 325 gr FTX LEVERevolution (Item #82750) · representative_gun, grain_ballistics archived
- Manufacturer Buffalo Bore — Heavy .450 Marlin Ammo — Rifle Ammunition (category listing) · grain_ballistics, representative_gun archived
Data & sources. Specs compiled from the Lindcott Armory reference; availability counted from 37 live factory loads; the trajectory is modeled (point-mass), not measured. See methodology. Spotted an error? Report it →
