As an Armourer and a prolific shooter of the SA80 in many service competitions , reliability was 2 different things.
As a shooter if I picked it up would it work as required? And for how many rounds.
As an Armourer when it came to inspections how many out of the company require repair, something the user will never know (as they would be repaired and returned to service)
The A1 was plagued with many many small faults that were mainly sorted when they changed over to the A2. But with age other faults came to light ( welds failing on the bodies and TMH’s)
I think the A 2 was slightly more reliable than the A1 but we had 15 years to get it sorted. But that dose not say the A2 was reliable just not as bad....
I found one big failing of the A2 fitted with the new handguard and down grip was the fact that you could grip the front grip and flex the barrel enough to pull shots well off target.
A reliable weapon should function AND be able to hit the target