What bullet diameter is 8x64mm S?

8x64mm S uses a 0.323″ (8.2 mm) diameter bullet.

Cartridge

8x64mm S

Caliber: 0.323″ · 8.2 mm
Introduced: 1912
Case: Rimless
Status: Obsolete

Buy this cartridge

Buy at Rivertown

Buying from Rivertown

Partner link

Velocity2,600–2,780 fps

Energy2,972–3,397 ft·lb · est.

Identity

Introduced: 1912
Status: Obsolete

Build

Case capacity: 69.5 gr H₂O
Case type: Rimless

Pressure & range

Max pressure: 58,740 psi
Eff. range: 350 yd

Ballistics

Representative trajectory · velocity only, no drag model · 100 yd zero0–800 yd

Drop Zero

Velocity only, no drag model: no published ballistic coefficient is on file for 8x64mm S, so this is the shape gravity alone gives the advertised velocity. Drag would steepen it. The tool below solves real loads through their published G1 or G7 model.

Open in Ballistic Compare

Parent case: —

Representative trajectory — modeled from a single velocity input (no published BC for this cartridge yet).

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 · verified

Measure	mm	in	✓
Bullet ⌀	8.20	0.323	✓
Neck ⌀	8.96	0.353	✓
Shoulder ⌀	10.85	0.427	✓
Shoulder angle	14°	—	✓
Base ⌀	11.95	0.470	✓
Rim ⌀	12.00	0.472	✓
Belt ⌀	n/a
Rim thickness	1.30	0.051	✓
Neck length	—	—	≈
Case length	64.00	2.520	✓
Overall length	87.50	3.445	✓

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. 8x64mm S is highlighted below.

Reloading costestimate cost per round vs factory

Estimate your cost per round and how it compares to factory. Inputs are yours — nothing is stored.

Powder $/lb Charge (gr) Bullet $/ea Primer $/ea Brass reuses Brass $/ea

Cost estimate only — not load data. Charge weight is your input; follow published manuals for safe charges.

Lineage

Family TreeOpen 8x64mm S in the interactive cartridge family tree

Connected reference

FirearmsFirearms in 8x64mm S ToolCompare ballistics

FAQs

What bullet diameter is 8x64mm S?: 8x64mm S uses a 0.323″ (8.2 mm) diameter bullet.
Is 8x64mm S still in production?: 8x64mm S is obsolete.

Sources & provenance

Standard C.I.P. (Commission Internationale Permanente) — C.I.P. TDCC — 8 x 64 S (Tab. I, rimless, p.62) · bullet ⌀ archived
Secondary Wikipedia — 8x64mm S · year, bullet ⌀, velocity, grain weights archived

Data & sources. Specs compiled from the Lindcott Armory reference; the trajectory is modeled (point-mass), not measured. See methodology. Spotted an error? Report it →