8.5 mm Messner Mag. Load Data & Reloading Guide
Also known as: 8.5mm Messner Magnum, 8.5×64mm Messner
About 8.5 mm Messner Mag.
The 8.5 mm Messner Magnum is a relatively new addition to the world of firearms, primarily emerging from the desire for a versatile, high-performance cartridge. Originally developed in the early 21st century by a small group of European enthusiasts, the cartridge sought to balance power, accuracy, and recoil management. Its designers envisioned a cartridge that would excel in both hunting and precision shooting competitions by offering superior ballistics in a medium-large rifle caliber.
Technically, the 8.5 mm Messner Magnum utilizes a rebated rim, allowing it to fit into actions designed for similar high-performance cartridges. It achieves its power from an extended case that holds a significant powder charge, propelling bullets with high velocity and energy. The typical bullet diameter is around 8.5 mm, which is approximately 0.335 inches, with typical bullet weights ranging from 200 to 250 grains. This range provides flexibility for different shooting applications, enhancing its versatility.
In terms of ballistic performance, the 8.5 mm Messner Magnum is known for maintaining high velocity and a flat trajectory over long ranges. This makes it an excellent choice for hunting large or difficult-to-reach game, where extended precision and energy retention are paramount. From a competition standpoint, the high ballistic coefficient of its bullets allows for superior wind resistance, which is advantageous in precision shooting and long-range competitions.
For reloaders, the 8.5 mm Messner Magnum offers several advantages. Its case design allows for consistent powder burn and efficient use of high-density powders, which can be tailored to optimize performance for specific bullets and barrel lengths. Additionally, reloading this caliber offers the opportunity to experiment with various bullet weights and types to further enhance its already impressive ballistic performance, tailoring loads specifically for hunting or competitive shooting scenarios. Furthermore, the availability of a wide array of bullets from manufacturers allows reloaders to fine-tune and customize their ammunition to extract maximum potential from the cartridge.
Technical Drawing

Technical Specifications
Start Calculating to Develop your own Load Data for 8.5 mm Messner Mag.
Use our professional ballistics calculator to develop safe and accurate load recipes for 8.5 mm Messner Mag..
Start CalculatingStandard Load Data — 8.5 mm Messner Mag.
Select your desired cartridge and bullet weight below to access the corresponding load table. From there, you can choose any listed load recipe and transfer it directly into the ballistics calculator for further refinement, optimization, and precision tuning.
.338 | 175gr | CutEdge ESP Raptor
.338 | 250gr | Nosler Partition Gold
.338 | 250gr | Sako Hammerhead
.338 | 165gr | TPM XTLD
.338 | 185gr | Barnes TTSX BT
.338 | 200gr | Nosler Ballistic Silver Tip
.338 | 210gr | Barnes TTSX BT
.338 | 225gr | Barnes TTSX BT
.338 | 210gr | Swift Scirocco
.338 | 225gr | Nosler Expansion Tip
.338 | 225gr | CutEdge LZR
.338 | 230gr | Lehigh Defense Match Solid
.338 | 172gr | Sax KDG-S
.338 | 220gr | Atomic 29 HP
.338 | 200gr | Alaska Bullet Works Kodiak SP SPBC
.338 | 138gr | Sax KJG-SR
.338 | 240gr | Lehigh Defense Match Solid
.338 | 245gr | Lehigh Defense Match Solid
.338 | 225gr | Woodleigh HS
.338 | 210gr | Nosler Partition
.338 | 230gr | Nosler CT FailSafe
.338 | 225gr | CutEdge Maximus
.338 | 225gr | Nosler AccuBond
.338 | 200gr | Alaska Bullet Works Kodiak SP SPFN
Frequently Asked Questions
The maximum pressure for 8.5 mm Messner Mag. is 63,817 psi | 4,400 bar.
8.5 mm Messner Mag. typically uses a Large Rifle Magnum (LRM) primer.
The case capacity of 8.5 mm Messner Mag. is approximately 106 grains of water (H₂O).