I've never had the issue myself and first I've ever heard of it. Has to be something in the sear I'm thinking. If it is a 3 shot burst it is full auto. So you fire a round, let go of the trigger and get a 3 shot burst consistently???
Something very strange here. You using stick mags or the drum although I don't see how that could make a difference.
Your correct to keep that thing at home till we sort it out. A call to Kahr is definitely in order.
In Memory of Paul "Dietrich" Stines.
Dad: Say something nice to your cousin Shirley
Dietrich: For a fat girl you sure don't sweat much.
Cue sound of Head slap.
RIP Muggsy & TMan
"If you are a warrior legally authorized to carry a weapon and you step outside without that weapon, then you become a sheep, pretending that JOCKO will not come today."