The differences between British and Australian L1A1, SLRs.

[Bruce_in_Oz]

Interchangeability was built into the specification agreed upon by the "Rifle Steering Committee" during the adoption of the L1A1 / C1. Essentially, it meant "modules" were interchangeable pretty much at any level, and gauging was, for all practical purposes, the same. Even the threads used on "inch" pattern rifles are the "nearest equivalent" to the original metric ones. For example, whilst you can swap the rear-sight assemblies, the "windage" adjustment screws are "almost" the same, but will not "go" completely. Metric vs BA. BA of course, being itself derived from the Swiss, METRIC, Thury clock-makers thread.

Here in Oz, we had a "fire-support / automatic rifle variant, the L2A1, essentially the same as the Canadian C2.

Woodwork variations occurred because different "timber" behaves differently under extremes of heat, cold and "stress". However, swapping between Imperial "patterns" was straightforward, as long as you had the correct screws, etc. for each pattern.

Brit. black plastic furniture will fit straight onto an Oz L1A1 and was issued in limited quantities during the "dying days" of the L1A1 in Oz service. Probably drop straight onto a C1

The interesting thing is that you can (usually) drop a complete L1A1 "upper" onto an FAL lower / TMH and vice-versa, and it will work. A LOT of effort seems to have gone into maintaining the mechanical dimensions of the rifle in its development. Which, of course, would make (rare) sense.

Then there are the Indian ones..........