Disagree, unless the full auto requires like 5 bullets or something (because in that case you'll always be 1 bullet short), it's probably a good idea to disable full auto fire if it's going to result in the burst being turned off mid-spray.
If all full auto is 3 bullets, then it's completely fine to turn it off if you're at 2 bullets, imo.
Also doesn't the picture show that there's 14 bullets in the AK 47? This might be something else.