Rifle Bolt Head Segmentation for Caliber Adaptation

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing rifle bolt designs face challenges in securely guiding locking elements and efficiently adapting to different cartridge ejection directions and caliber changes, leading to increased costs due to the need for multiple bolt heads.

Innovation Solution

A bolt head with a standardized base body and detachable rim sections that can be easily reconfigured for various ejection directions and calibers, featuring an inwardly curved guide surface for secure locking element guidance and a simplified locking mechanism using a sleeve-shaped control element.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a complete bolt head is provided for each caliber and ejection direction, then the guidance of locking elements is secure and the fit is precise, but the device complexity and cost increase significantly

Engineering Contradiction:
Improveguidance of locking elementsVSAvoidnumber of bolt heads
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The bolt head is divided into two detachable parts: a base body and a rim section. The rim section can be exchanged while the base body remains, allowing different ejection directions and calibers without replacing the entire bolt head. This segmentation maintains reliable locking element guidance through the standardized base body while reducing the number of complete bolt heads needed.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The base body is designed as a universal component that can accommodate multiple rim sections for different calibers and ejection directions. The standardized locking element guidance features in the base body serve multiple functions across different configurations, eliminating the need for separate complete bolt heads for each variant.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Manufacturing precision

If multiple complete bolt heads are manufactured for different calibers and ejection directions, then the fit and precision are maintained, but the manufacturing cost increases

Engineering Contradiction:
Improvefit of bolt componentsVSAvoidmanufacturing cost
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

By segmenting the bolt head into a standardized base body and interchangeable rim sections, the manufacturing process can focus on producing one precise base body design that serves multiple purposes. The rim sections can be manufactured with specific caliper and ejection direction features without requiring complete bolt head production for each variant, reducing overall manufacturing costs while maintaining precision through standardized interfaces.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The design allows changing caliber and ejection direction parameters by swapping rim sections rather than manufacturing entirely new bolt heads. The standardized base body maintains consistent precision features, while only the variable parameters (caliber, ejection direction) change through the interchangeable rim sections, significantly reducing manufacturing costs.

Inventive Principle:
Principle #35Parameter changes

3Device complexity

If a standardized base body with detachable rim sections is used, then the cost and complexity are reduced, but the secure guidance of locking elements must be maintained

Engineering Contradiction:
Improvenumber of partsVSAvoidguidance of locking elements
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The segmentation into base body and rim section is designed so that the critical locking element guidance features are located in the standardized base body, which remains constant across all configurations. This ensures reliable guidance while allowing the rim section to be detached and replaced for different calibers and ejection directions.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The standardized base body serves as a universal platform that maintains reliable locking element guidance across all rim section configurations. The multi-functional base body ensures consistent performance for different calibers and ejection directions without compromising the secure guidance of locking elements.

Inventive Principle:
Principle #6Universality (Multi-functionality)

4Manufacturing precision

If complete bolt heads are replaced for caliber changes, then the precision and fit are maintained, but the time and cost for adaptation increase

Engineering Contradiction:
Improvefit of bolt headVSAvoidtime for caliber change
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The detachable rim section design allows caliber changes by simply removing the old rim section and installing a new one on the standardized base body, rather than replacing the entire bolt head. This segmentation enables rapid adaptation while maintaining the precise fit of the standardized base body interface.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The design introduces dynamic adaptability by allowing the rim section to be changed without replacing the entire bolt head assembly. This dynamic configuration capability reduces the time for caliber changes from requiring complete bolt head replacement to a simple rim section swap, while maintaining precision through the standardized interface.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP4438990B1Closure head of a gun bolt and gun bolt with such a closure head
Publication Date: 2026.03.11 L & O HUNTING GRP
  • EP4438990B1 patent drawingFigure 1~2
  • EP4438990B1 patent drawingFigure 3~4
  • EP4438990B1 patent drawingFigure 5~6

AI summary

The invention relates to a bolt head (9) of a rifle bolt (4), comprising a base body (17), a breech face (18) arranged on the front of the base body (17), and a ring-shaped rim (20) surrounding the breech face (18). The rim (20) is formed by several rim parts (21, 22) detachably attached to the base body (17).