SA80 History: XL60 Series in 4.85mm

Published on May 10, 2017
Duration: 26:58

This guide details the disassembly of the XL60 Series prototypes, precursors to the SA80. It highlights key internal components like the rotating bolt and gas piston system, drawing comparisons to designs like the AR-180 and G43. The overview also points out critical design flaws, such as unsupported bolt lugs and foreign material ingress points, as explained by Ian McCollum's expert analysis.

Quick Summary

The XL60 Series prototypes, precursors to the SA80 rifle, were developed at RSAF Enfield and primarily chambered in 4.85x49mm. They featured a short-stroke gas piston system and a rotating bolt, but suffered from critical design flaws like unsupported bolt lugs and foreign material ingress, impacting reliability.

Chapters

  1. 00:00Introduction to XL60 Series
  2. 01:45Design Team & Engineering Philosophy
  3. 04:22Disassembly & Internal Mechanics
  4. 07:30Gas System & Reliability Issues
  5. 09:23Evolution of Controls
  6. 14:40B-Series & LSW Experiments
  7. 23:00Live Fire & Final Assessment

Frequently Asked Questions

What were the precursors to the British SA80 rifle?

The precursors to the British SA80 (L85) rifle were the XL60 series prototypes, developed between 1972 and 1974 at RSAF Enfield. Only 12 were produced, primarily chambered in the experimental 4.85x49mm cartridge.

What were the main design flaws of the XL60 Series prototypes?

Key design flaws included unsupported bolt lugs due to material milling for the extractor and significant ingress of foreign material into the action through handguard vents and the charging handle slot, impacting reliability.

What cartridge did the XL60 Series prototypes primarily use?

The XL60 Series prototypes were primarily chambered in the experimental British 4.85x49mm cartridge. One prototype was also produced in 5.56mm NATO.

How did the XL60 Series design team approach firearm development?

The design team of 26 individuals had no prior experience designing or firing rifles, treating the project as a generic engineering task. This led to missed 'small lessons' crucial for firearm reliability.

More Gunsmithing & DIY Videos You Might Like

More from Forgotten Weapons

View all →