Lindcott Armory Pistol · SAAMI
.45 GAP
Glock's .45-caliber cartridge in a 9mm-length case, allowing a standard-frame Glock to chamber .45-caliber bullets.
- Caliber
- 0.452″ · 11.48 mm
- Introduced
- 2003
- Case
- Rebated
- Parent
- .45 ACP
- Primary use
- Law Enforcement, Self Defense
- Status
- Active
- Introduced
- 2003
- Type
- Pistol
- Origin
- United States
- Inventor
- Ernest Durham / Glock / CCI-Speer
- Manufacturer
- Speer, various
- Standard
- SAAMI
- Status
- Active
- Availability
- Limited
- Case capacity
- 21.4 gr H₂O
- Twist (typical)
- 1:16
- Primer
- Small Pistol
- Case type
- Rebated
- Max pressure
- 23,000 psi
- Eff. range
- 50 yd
- Max range
- 100 yd
- Recoil
- 3–5 ft·lb
- Subsonic
- Capable
Ballistics
- By real loads
- 837–1,090 fps · 31 loads
- Parent case
- .45 ACP
Representative trajectory — modeled from a single velocity input (no published BC for this cartridge yet).
Performance
Buy links open .45 GAP ammunition at Rivertown Munitions.
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 ⌀ | 11.48 | 0.452 | ✓ |
| Neck ⌀ | 12.01 | 0.473 | ✓ |
| Shoulder ⌀ | n/a | ||
| Shoulder angle | n/a | ||
| Base ⌀ | 12.09 | 0.476 | ✓ |
| Rim ⌀ | 11.94 | 0.470 | ✓ |
| Belt ⌀ | n/a | ||
| Rim thickness | 1.24 | 0.049 | ✓ |
| Neck length | n/a | ||
| Case length | 19.18 | 0.755 | ✓ |
| Overall length | 27.18 | 1.070 | ✓ |
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. .45 GAP is highlighted below.
Factory loads
In production — 31 active loads across 12 brands. Top 15 shown · see all 31 →.
| Brand | Load | Grain | Bullet | FPS | ft·lb | BC |
|---|---|---|---|---|---|---|
| Federal | HST JHP | 185 | HST JHP | 1,090 | 488 | — |
| Speer | Gold Dot | 185 | GDHP | 1,090 | 488 | — |
| Speer | Lawman | 185 | TMJ | 1,090 | 488 | — |
| Hornady | Custom XTP JHP | 185 | XTP JHP | 1,050 | 453 | — |
| Speer | Gold Dot HP | 185 | Gold Dot HP | 1,050 | 453 | — |
| Remington | Golden Saber JHP | 185 | Golden Saber JHP | 1,015 | 423 | — |
| Hornady | Critical Defense | 185 | FTX | 1,000 | 411 | — |
| Hornady | Critical Defense FTX | 185 | FTX | 975 | 390 | — |
| Hornady | Custom XTP | 200 | XTP HP | 975 | 422 | — |
| Speer | Gold Dot | 200 | GDHP | 975 | 422 | — |
| Cor-Bon | DPX 185gr | 185 | DPX | 950 | 371 | — |
| Hornady | Custom XTP JHP 200gr | 200 | XTP JHP | 940 | 392 | — |
| Speer | Gold Dot JHP 200gr | 200 | Gold Dot | 940 | 392 | — |
| Blazer Brass | FMJ | 230 | FMJ Aluminum | 880 | 395 | — |
| Blazer Brass | FMJ | 230 | FMJ | 880 | 395 | — |
Velocities are manufacturer-stated (test-barrel). Discontinued loads dimmed.
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 .45 GAP
12 models in the database chamber .45 GAP. Browse all →
Lineage
Connected reference
History
Developed in 2003 by Glock and CCI-Speer to allow Glock to offer a .45-caliber pistol on their standard-frame (not large-frame) action. The short case fits in a 9mm-sized frame while delivering .45 ACP ballistics. Several US state police agencies adopted it, including New York State Police, South Carolina Highway Patrol, and others. Ammunition availability has fluctuated; some agencies have transitioned back to 9mm.
FAQs
- What twist rate does .45 GAP use?
- .45 GAP typically uses a 1:16 twist rate.
- What bullet diameter is .45 GAP?
- .45 GAP uses a 0.452″ (11.48 mm) diameter bullet.
- Is .45 GAP still in production?
- .45 GAP is active; typical availability is limited.
- What is .45 GAP used for?
- .45 GAP is primarily used for law enforcement, self defense.
- What is .45 GAP based on?
- .45 GAP is derived from the .45 ACP case.
Sources & provenance
- StandardSAAMI — ANSI/SAAMI Z299 — Cartridge & Chamber Drawingsarchived
- StandardC.I.P. — C.I.P. TDCC — Tables of Dimensions of Cartridges and Chambers
Data & sources. Specs compiled from the Lindcott Armory reference; availability counted from 31 live factory loads; the trajectory is modeled (point-mass), not measured. See methodology. Spotted an error? Report it →