Bofors 40mm Mk4 Gun

Manufacturer: BAE Systems
Category: Artillery & Indirect Fire
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Caliber & Firepower 40mm / 300 rpm / 3P airburst ammo.
Maximum Effective Range 12,500 meters (7.8 miles).
Mobility / Platform Type Light 2,300 kg naval mount; no deck penetration.
Fire Control & Targeting System Fully remote; integrates with ship CMS/radar.

Full Specifications

1. General Information

System Name	Bofors 40 Mk4 Naval Gun System
Manufacturer	BAE Systems
Country of Origin	Sweden
Type / Role	Lightweight Multi-Purpose Naval Cannon / Anti-Aircraft Gun
Caliber	40 mm
Year Introduced	2012
In Service	Yes
Unit Cost	USD 3.5 Million – 5.0 Million (estimated)
Crew Required	Remotely operated (0 on mount; local manual backup option)
Platform Type	Vessel-Mounted / Modular Deck Launching / Containerized
Power Source	Shipboard Electric System (No hydraulic lines)

2. Performance & Firepower

Maximum Effective Range	12,500 m (7.8 miles)
Minimum Range	< 100 m
Rate of Fire (Sustained / Burst)	300 rounds per minute
Accuracy (CEP)	Highly precise computer-controlled burst pattern
Elevation Range	-20° to +80°
Traverse Range	360° (unlimited via slip ring)
Recoil System	Hydraulic damper with spring return
Reload Time	Continuous auto-loading / Rapid multi-magazine feed change

3. Ammunition & Warhead Options

Compatible Ammunition	Programmable 3P, PFHE, HE-T, AP-T, TP-T
Caliber Standard	NATO 40 × 365 mm R
Warhead Type	Prefragmented High-Explosive / Armor-Piercing / Proximity Airburst
Warhead Weight	0.975 kg (Complete cartridge: 2.5 kg)
Fuse Type	6-mode Programmable (Impact, Proximity, Time Delay, etc.)
Muzzle Velocity	1,012 m/s (using 3P ammunition)
Guidance	Unguided ballistic projectile (Fuzing altered via fire control)
Effective Burst Radius	Optimizable based on 3P airburst mode selected

4. Fire Control & Targeting Systems

Fire Control System	Fully Digital Modular Architecture / Integrated Ballistic Computer
Aiming System	Remotely slaved to Ship Combat Management System (CMS)
Communication Link	Tactical Data Link / Secure Ethernet System Architecture
Night Operation	Supported via on-mount TV camera & IR/Thermal tracking options
Automation Level	Fully Automated Remote Operation
Targeting Assistance	On-mount muzzle velocity radar integration

5. Launcher / Platform & Mobility

Platform Type	Naval Combatant Deck Mount (Frigates, Corvettes, Patrol Ships)
Vehicle Model	Custom Naval Hull / Palletized Deck System
Mobility Range	N/A (Dependent on host vessel)
Top Speed	N/A (Slew rate up to 85°/sec)
Ground Clearance	N/A
Setup / Emplacement Time	Instant operational transition from standby state (< 0.5 sec)
Transportability	Air/Sea/Land logistics cargo compatible

6. Protection & Survivability

Armor Level	Weatherproofing & fragment protection cupola
CBRN Protection	Remotely operated; crew remains safely within protected hull
Counter-Battery Radar Integration	Yes (Can slave to ship sensor networks)
Smoke Launcher System	External (Ship-dependent configuration)
Shoot-and-Scoot Capability	N/A (Naval dynamic track-while-maneuvering capable)
Signature Reduction	Low Radar Cross Section (RCS) geometric shield structure

7. Command, Control & Networking

C2 System	Integrated Combat Management System (CMS) / Local Gyro Unit
Connectivity	Secure military data bus architecture
Network Capability	Yes (Multi-layer air defense network integration)
Operation Mode	Networked Automated Fire Mission / Gyro-Stabilized Local Backup
Compatible Systems	Radar, Electro-Optical Directors, Laser Rangefinders

8. Operational History

Primary Operators	United Kingdom, Sweden, Finland, Brazil, Japan
Combat Proven	Yes (40mm family lineage proven across multiple global conflicts)
Operational Deployment	Global maritime deployments, North Sea, Baltic Sea, Pacific Rim
Conflict History	Falklands War (legacy variants), modern anti-piracy, C-UAV engagements
Notable Feature	Minimal deck penetration required for lower compartment safety

9. Dimensions & Weight

System Weight	2,300 kg (5,100 lbs) excluding ammunition
Barrel Length	2.8 meters (9 ft 2 in)
Vehicle Weight	N/A
Dimensions (L×W×H)	Height less than 2.0 meters on deck
Transport Configuration	Fixed crate configuration for dockyard crane-in installation

10. Maintenance & Support

Maintenance Cycle	Barrel life up to 5,000 rounds fired
Field Servicing Time	Low maintenance requirement due to all-electric architecture
Spare Parts Availability	High (Global BAE Systems supply chain network)
Training Requirement	2–4 weeks operator and technician courses
Support Package	OEM Integrated Logistic Support (ILS)

11. Economic / Procurement Data

Estimated unit cost	USD 3.5 Million – 5.0 Million
Cost per Round	Variable (Standard HE: Low; 3P Programmable: Moderate-High)
Country Procurement Program	Royal Navy (Type 31 Frigates), Finnish Navy, Brazilian Navy
Export Status	Export Approved (Subject to Swedish & Global Arms Controls)
Manufacturer Website	BAE Systems - Bofors 40 Mk4

Our Rating

The overall rating is based on review by our experts

Combat Effectiveness 8 / 10
Performance 8 / 10
Technology 8 / 10
Firepower 8 / 10

PROS

Multi-Target Versatility: Seamlessly engages drones, missiles, fast shore craft, and armored ground targets.
Smart Ammunition: Employs advanced 3P programmable ammo with six distinct electronic fuzing modes.
Lightweight & Compact: Weighs under 2,300 kg, allowing installation on smaller patrol vessels and fast interceptors.
Lightning Reaction Time: Transitions from safe standby to target engagement in under half a second.
Dual Control Reliability: Fully automated remote radar operation with local gyro-stabilized manual backup.

CONS

Limited Magazine Capacity: Holds 100 ready-to-fire rounds, requiring disciplined fire-burst management.
High Munitions Cost: Specialized 3P programmable rounds are vastly more expensive than standard high-explosive tracer shells.
No Internal Sensor Array: Relies heavily on external shipborne radar or electro-optical directors for maximum unassisted tracking.
Armor Penetration Limits: While highly lethal to light armor, the 40mm caliber struggles against heavy, modern main battle tanks.
Logistical Footprint: Requires specialized technicians to maintain its complex digital fire control matrix and electric drives.

Bofors 40mm Mk4: The Ultimate Modern Autocannon

The Bofors 40mm autocannon family stands as one of the most legendary lineages in military history. Originating in Sweden before World War II, it established itself as the gold standard for medium-caliber anti-aircraft fire. Today, its ultimate evolution—the Bofors 40mm Mk4—has been completely modernized by BAE Systems for the 21st-century battlespace.

Transitioning from a legacy point-defense weapon to a highly integrated, digital multi-purpose system, the Bofors 40mm Mk4 is designed to counter low-radar-cross-section threats. It excels in littoral warfare, law enforcement, and close-in defense operations.

Manufacturer and Origin

The system is designed and manufactured by BAE Systems Bofors AB, based in Karlskoga, Sweden. BAE Systems continues to refine this platform, cementing its role across NATO and allied naval fleets worldwide.

Speed and Range

The weapon delivers exceptional ballistic performance, firing the standard 40x365mmR cartridge at a blistering muzzle velocity of 1,012 meters per second. It features an adjustable rate of fire maxing out at 300 rounds per minute. The system boasts a maximum effective ballistic range of 12,500 meters (7.8 miles), ensuring defensive coverage long before a threat reaches a vessel’s hull.

Technology and Cost

The modern success story of the Bofors Mk4 lies in its fully digitized, modular architecture and its integration with 6-mode programmable 3P (Prefragmented, Programmable, Proximity-fuzed) ammunition. This allows the operator to shift from warning shots to airburst patterns in less than 0.5 seconds, effectively destroying asymmetric threats like kamikaze drones, anti-ship missiles, and fast attack craft. Depending on mount configuration, fire control packages, and integration requirements, the estimated unit cost ranges between USD 2.5 Million to 4 Million.

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