hi ,took my son with me to shoot he is 20 years old. just started showing intrest in shooting. he was a little tense and about 3 times he made the gun shoot like a fully auto a very very fast 2 rounds. i tried and could not do it and i shot 300 rounds. can someone explain this to me i mean these 2 rounds seem like they came out about the same time and it happend 3 differnt times. thank for any info.