Autocannon · Military · Not SAAMI standardized · Not standardizedObsolete
37x145mmR
The 37x145mmR was a rimmed fixed-ammunition cannon round for the US 37mm M4 aircraft cannon (standardized 1942), later replaced by the M9..
- Caliber
- 1.4567″ · 37 mm
- Introduced
- 1942
- Case
- Rimmed
- Primary use
- Military
- Status
- Obsolete
- Obsolete
- Obsolete
- Introduced
- 1942
- Type
- Autocannon
- Origin
- United States
- Inventor
- US Army Ordnance (approx: adopting body)
- Standard
- Military · Not SAAMI standardized · Not standardized
- SAAMI
- Not SAAMI standardized
- Obsolete
- Obsolete
- Status
- Obsolete
- Availability
- Not commercially available
- Case capacity
- 2373.3 gr H₂O
- Primer
- Percussion (military)
- Case type
- Rimmed
- Eff. range
- 1500 yd
- Max range
- 4500 yd
- Recoil
- 4,359.6–4,494.7 ft·lb
Ballistics
Velocity only, no drag model: no published ballistic coefficient is on file for 37x145mmR, 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.
Wikipedia · approximate| Measure | mm | in | ✓ |
|---|---|---|---|
| Bullet ⌀ | 37.00 | 1.457 | · |
| Neck ⌀ | 38.61 | 1.520 | |
| Shoulder ⌀ | 45.10 | 1.776 | |
| Shoulder angle | 24° | — | |
| Base ⌀ | 47.51 | 1.870 | |
| Rim ⌀ | 48.51 | 1.910 | |
| Belt ⌀ | n/a | ||
| Rim thickness | 4.96 | 0.195 | |
| Neck length | 38.20 | 1.504 | |
| Case length | 145.00 | 5.709 | |
| Overall length | 233.54 | 9.194 | |
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. 37x145mmR is highlighted below.
Missing a dimension for 37x145mmR? 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.
Connected reference
History
The 37x145mmR was a rimmed fixed-ammunition cannon round for the US 37mm M4 aircraft cannon (standardized 1942), later replaced by the M9.
FAQs
- What bullet diameter is 37x145mmR?
- 37x145mmR uses a 1.4567″ (37 mm) diameter bullet.
- Is 37x145mmR still in production?
- 37x145mmR is obsolete; typical availability is not commercially available.
- What is 37x145mmR used for?
- 37x145mmR is primarily used for military.
Sources & provenance
Data & sources. Specs compiled from the Lindcott Armory reference; the trajectory is modeled (point-mass), not measured. See methodology. Spotted an error? Report it →
