Kbsp wz. 38M
- Category
- Rifle
- Barrel
- 625 mm
- Weight, empty
- 4.50 kg
- Introduced
- 1938
About
What it is, and why it matters
The Kbsp wz. 38M was a Polish gas-operated semi-automatic rifle designed by engineer Jozef Maroszek and issued in very small numbers to the Polish Army during the September 1939 campaign. Chambered for the 7.92x57mm Mauser cartridge already standard in the Polish service Mauser rifles, it used a gas tube mounted beneath the barrel to drive a tilting-bolt locking system reminiscent of the Browning Automatic Rifle, with the bolt cammed upward to lock against the front edge of the loading aperture in the top of the receiver. The rifle fed from a fixed ten-round box magazine charged from above using standard Mauser stripper clips, and was fitted with a tangent leaf rear sight graduated from 300 to 2,000 metres. Only about 150 examples were completed at the Warsaw arsenal before the German invasion halted production, making the wz. 38M one of the rarest service rifles of the Second World War; surviving examples are marked 'Zrb.2' for the arsenal that built them, and only a handful are known to exist today.
Designed by Jozef Maroszek, the same engineer behind Poland's secretive wz. 35 'Ur' anti-tank rifle, the kbsp wz. 38M might have given Polish infantry a self-loading rifle on par with the American Garand had the war held off a few more years. Instead only around 150 were built before the panzers rolled in, and the rifles vanished into the chaos of 1939 - so completely that for decades collectors doubted any had survived, until a handful resurfaced bearing the cryptic 'Zrb.2' arsenal stamp.
Maroszek - already famous as the designer of the wz. 35 anti-tank rifle - was one of the winners of Poland's 1934 self-loading rifle trials, and prototypes of his rifle were refined from 1936 to 1938 before the wz. 38M pattern was adopted. Production was crippled by shortages of specialised tooling and the worsening political situation; estimates of completed rifles range around 150, with the highest recorded serial number near 1054. The fixed magazine and stripper-clip loading kept the design compatible with existing Polish ammunition logistics built around the wz. 98 Mauser, and the fire-control group offered semi-automatic fire only, with no full-automatic capability.
Specification
Everything measured
IdentityWhat it is, who built it and when.
- Manufacturer
- Państwowa Fabryka Karabinów (State Rifle Factory, Warsaw)
- Category
- Rifle
- Country
- Poland
- Status
- Prototype
- Produced
- 1938 to 1939
DimensionsAs issued, without a magazine or an optic.
- Barrel
- 625 mm
- Overall length
- 1100 mm
- Weight, empty
- 4.50 kg
ActionHow it cycles, what trips it, and what feeds it.
- Action
- Gas operated
- Firing mechanism
- Hammer fired
- Trigger
- Semi auto
- Capacity
- 10
- Magazine
- Internal
MaterialsEach swatch is the material itself, not a colour chosen to stand for it.
- Frame
- Steel
- Barrel
- Steel
- Stock
- Walnut
- Finish
- Blued
BallisticsFrom the service cartridge, not a handload.
- Muzzle velocity
- 745 m/s
- Effective range
- 600 m
- Maximum range
- 2000 m
Trajectory
What the round does downrange
Solved from the muzzle figures and the bullet. The dashed rule is the effective range on the record, and the crosses are the steps the solver returned.
No load solved for this record yetThe flight path is computed from a cartridge and a bullet. This record has no ammunition filed against its chambering, so there is nothing to solve.
Features
What it has
What the record lists as fitted, drawn from the catalogue.
Gas operated tilting bolt
Fixed ten round magazine
Mauser stripper clip loading
Tangent leaf rear sight
Under barrel gas tube
Wooden full length stock
Standing
How it compares
Each figure against the firearms of the same type and cartridge that record it, or of the same type where that cartridge has too few. Positions are read to the nearest tenth.
| Measurement | This firearm | Median | Position |
|---|---|---|---|
| Empty weightAmong 36 7.92x57mm Mauser rifles | 4.50 kg | 4.00 kg | Heavier than about 90% |
| Overall lengthAmong 35 7.92x57mm Mauser rifles | 1100 mm | 1105 mm | Shorter than about 70% |
| Barrel lengthAmong 35 7.92x57mm Mauser rifles | 625 mm | 600 mm | Longer than about 60% |
| Magazine capacityAmong 36 7.92x57mm Mauser rifles | 10 | 5 | Among the largest capacities |
Answers
Questions about the Kbsp wz. 38M
How much does the Kbsp wz. 38M weigh?
The Kbsp wz. 38M weighs 4.50 kg (9.92 lb) empty.
What caliber is the Kbsp wz. 38M?
The Kbsp wz. 38M is chambered in 7.92x57mm Mauser.
How many rounds does the Kbsp wz. 38M hold?
The Kbsp wz. 38M holds 10 rounds, fed from an internal magazine.
How long is the Kbsp wz. 38M?
The Kbsp wz. 38M is 1100 mm (43.3 in) long overall, with a 625 mm (24.6 in) barrel.
Who makes the Kbsp wz. 38M?
The Kbsp wz. 38M is made by Państwowa Fabryka Karabinów (State Rifle Factory, Warsaw) (Poland). It was designed by Jozef Maroszek.
When was the Kbsp wz. 38M introduced?
The Kbsp wz. 38M was introduced in 1938 and discontinued in 1939.
How does the Kbsp wz. 38M operate?
The Kbsp wz. 38M uses a gas operated action, and its firing mechanism is hammer fired.
Compatibility
Which parts fit this firearm
Studio
Every part that mounts on this, resolved
Not a list the maker typed out: the answer comes from the mounts this firearm exposes and the interface each part needs, so it stays right when either one changes.
- Every part that mounts on any firearm in the catalogue
- Interface standards, platforms and fit overrides
- The same answers through the API and the MCP server
Requires a signed-in GunSpec account on the Studio plan. The answer is computed per part, so it is not part of the public record.
Provenance
What the record holds
Every figure above was taken from one of these pages. The confidence reflects how much of the record came from a page a claim can be checked against.
In service
- Polish Army (Wojsko Polskie)
- 1938
Provenance
Confidence in this record
70%
Stockists
Where to buy
Offers link straight to the shop. GunSpec never takes the order.
No shop has listed this firearm yet
Stock and prices come from the shops themselves. If you sell this firearm, you can list it and it appears here.
List a firearmMCP
Ask an assistant about it
The same record, reached the way a person asks for it rather than the way a program does.
Ask GunSpec
Works with
Point an MCP client at GunSpec and it answers from the catalogue rather than from memory. A free key covers the read tools.
API
The call that returns this record
The same fields, in the same units, from the same endpoint the page reads.
curl --request GET \ --url 'https://api.gunspec.io/v1/firearms/kbsp-wz-38m' \ --header 'X-API-Key: your_key'{ "id": "kbsp-wz-38m", "name": "Kbsp wz. 38M", "manufacturer": { "id": "fabryka-karabinow", "name": "Państwowa Fabryka Karabinów (State Rifle Factory, Warsaw)", "countryCode": "PL", "foundedYear": 1919, "website": null, "logoUrl": null, "description": null, "status": null, "defunctYear": null, "stateOwned": null, "makesFirearms": null, "parentId": null, "predecessorId": null, "createdAt": "2026-06-21 23:00:46", "updatedAt": "2026-06-21 23:00:46", "version": "bd93132d7e2be1664877c0d3b0962c53759f40ccb994a87ae462ccbd2553bdc9" }, "category": { "id": "rifle", "name": "Rifle", "description": "Long-barreled firearms designed for accurate shooting" }, "country_of_origin": "PL", "year_introduced": 1938, "barrel_length_mm": 625, "weight_empty_g": 4500, "action_type": "gas_operated"}