If your mag has the same effect, take a look at the trigger, hammer and striker assembly on your friends guns. One of those could be worn out and is slipping during normal use. On a related maintenance note, check your outer barrel, I've seen two similar guns have the outerbarrel disconnect from the ejection port cover, rendering them useless.
Every word ever written will fall short, of it's intent
Even sung, or spoke, or screamed, they will betray what they had meant.