Reliability - I've had stoppages with the A1, mostly magazine related because the radway green aluminium magazines were tonk, and a poor substitute for the colt mags the rifle was designed for.
I also had the bolt handle stoppage where the case bounced back into the ejection port.
The A2 - things got better, but I must have been issued a rifle with the mightiest return spring known to the REME because it was prone to short stroking.
I've had a rifle fail to chamber a round and had the 'dead man's click' fortunately on the ranges - unfortunately during a competition.
Things are constantly improving, I realise that the immediate action drill includes a lot of magazine related drills during the weapon handling tests. Issuing EMAGs will be a help I expect.
Someone told me last year what the pamphlet dictated people should clean the A2 at, I can't remember the exact number - but it was over a thousand rounds.
When the A2 was trialled there were tests conducted in Saudi that were written up in a military doctrine journal,and even with burying the rifle in sand, the instances of stoppages were very, very low.
Things are getting better all the time. But do remember - real men go belt fed!
