Rifle · Proprietary
.308 Winchester Ackley Improved
Ackley Improved version of the .308 Winchester; widely discussed in precision shooting communities for its improved case capacity and reduced body taper..
- Caliber
- 0.3079″ · 7.82 mm
- Introduced
- 1952
- Case
- Rimless
- Parent
- .308 Winchester
- Status
- Active
- Introduced
- 1952
- Type
- Rifle
- Origin
- United States
- Inventor
- P.O. Ackley
- Standard
- Proprietary
- Status
- Active
- Availability
- Uncommon
- Primer
- Boxer Large Rifle
- Case type
- Rimless
- Max pressure
- 62,000 psi
- Eff. range
- 700 yd
Ballistics
Velocity only, no drag model: no published ballistic coefficient is on file for .308 Winchester Ackley Improved, 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
- .308 Winchester
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.
SAAMI · approximate| Measure | mm | in | ✓ |
|---|---|---|---|
| Bullet ⌀ | 7.82 | 0.308 | ~ |
| Neck ⌀ | 8.72 | 0.343 | ~ |
| Shoulder ⌀ | — | — | |
| Shoulder angle | 40° | — | ~ |
| Base ⌀ | 11.96 | 0.471 | ~ |
| Rim ⌀ | 12.01 | 0.473 | ~ |
| Belt ⌀ | n/a | ||
| Rim thickness | 1.37 | 0.054 | ~ |
| Neck length | — | — | |
| Case length | 51.16 | 2.014 | ~ |
| Overall length | 71.12 | 2.800 | ~ |
Missing a dimension for .308 Winchester Ackley Improved? Some case measurements aren't in a published SAAMI/CIP drawing yet. Have a factory or reamer print? Send it → — verified hard-to-find data earns a free Lindcott sticker.
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.
Lineage
Connected reference
History
The .308 AI is one of the more commonly discussed Ackley Improved cartridges due to the .308's dominant position in precision rifle shooting. In practice the gains are modest — 50–80 fps — because the .308 already has a reasonably efficient case design. It requires custom chambering and is not in common factory production.
FAQs
- What bullet diameter is .308 Winchester Ackley Improved?
- .308 Winchester Ackley Improved uses a 0.3079″ (7.82 mm) diameter bullet.
- Is .308 Winchester Ackley Improved still in production?
- .308 Winchester Ackley Improved is active; typical availability is uncommon.
- What is .308 Winchester Ackley Improved based on?
- .308 Winchester Ackley Improved is derived from the .308 Winchester case.
Sources & provenance
- Reference Publishers Development Corp. (P.O. Ackley) — Handbook for Shooters and Reloaders, Vol. I & II (P.O. Ackley) · bullet ⌀, velocity, grain weights, year
- Reference Gun Digest / Krause (F+W Media) — Cartridges of the World — .308 Winchester Improved / Ackley section · velocity, bullet ⌀
Data & sources. Specs compiled from the Lindcott Armory reference; the trajectory is modeled (point-mass), not measured. See methodology. Spotted an error? Report it →