My AR fired a two shot burst

nope that was Dr. Emerson out of Texas
Beretta 92SBF

Syn…
There are large numbers of ARs out there on the used market with a partial M16 parts load
most owners don’t have a damn clue
last year at a Cabela’s I saw an M2 Carbine on the used rifle rack with a M2 marked receiver, don’t matter how the rest of the rifle is configured thats a Machinegun receiver and the “experts” at Cabelas had no clue until I pointed it out to them, was even in their stupid bound book as a M2!
point is the average Joe can’t tell you what parts are in his guns

You want a good read Google up the John Lawmaster case out of OK
ATF booted in his door while he was at work and later charged him for having an AR w/ M16 internals
yeah “intent” saved him but only after thousands of unrecoverable dollars in legal fees

and remember for every Lawmaster there are dozens whose luck wasn’t as good in Federal District Court

I don’t believe that Riverside meant to imply that you were thinking you could not be prosecuted for an accidental double fire.

I am sure that he only means to point out (to all who might read this) the fact that ATF does not particularly care how it happened, just the fact that it did happen is enough for them.
And if it is the same WI shooter that I know of, he was eventually pardoned for the incident, but only after a lot of court time and legal expense. The gun I know of was found to have a mechanical failure and he was absolved of guilt. But….. even after the fault was confirmed and acknowledged by ATF, ATF was still pushing for prosecution for some time after. Public exposure and the multiple witnesses in his defense may have played a big part in them eventually calling off the dogs.
And he did spend some time in the slammer too……

ROTFLMAO!
Yeah very poor reading comprehension on my part there
BUSTED 😆 😆 😆

You feel better now dear?

actually unintended 2 round bursts can still get you in the crowbar hotel Syn…happened to some clown in WI a few years back when his AR was doubling at his local range. Turned out there was a few M16 internals inside it and while he claimed the gun was purchased that way used, didn’t matter…don’t pass go, go straight to jail in his case

rubber bands are more or less legal depending on your state
in Minnesota tho any trigger activation device in and of itself is a felony under state code…yes ANY of them, all are classified even without a firearm as an unregistered machine gun in this state.

now just for informational purposes even a boot lace can be used to convert many semi autos to full auto
GI were doing this shit to M1 Garands way back in WWII
You make a loop at either end of the lace running one loop over the operating rod or bolt handle, slip the other end through the butt swivel then the other loop over the trigger.
Lace length is critical, idea is you want everything taut but not enough to depress the trigger. To fire you simply squeeze the lace at the pistol grip letting go to stop cycling.
Turned a number of CIIs on to this old trick back in the 90s who started registering Shoestrings with NFA branch as post sample NFA which led to ATF ending up with serious egg on their face when these registered machine guns were used in a few Defense exhibits as an example of how silly the extremes ATF will go to define a machine gun
last I heard NFA branch no longer accepts registration of shoe string conversions but you can bet your ass they WILL prosecute ya for one.

my guess is RC is on the money but check out your lowers internals just to be sure there isn’t a M16 hammer, trigger or disconnector in there
if it was a lower some assclown assembled god knows whats inside it
and if its a real old lower from prior to 82′ it was still legal to build ARs with full M16 lock-work. Early aftermarket lowers incorporated selector stops to prevent the M16 selector from going to the FA position. Those had a habit of doubling

Yep the sear slipped.

It can happen, but really a new sear probably is in order.

You could be double tapping the trigger also as roachcreek stated.