The ATF has ruled that a DIAS is a "machine gun" in and of itself, regardless of whether it is installed in a firearm.
: When used with a full-auto capable trigger and bolt carrier group, it allows the weapon to fire continuously as long as the trigger is held. Drop In Auto Sear Keychain
: These are designed to provide a crisper, lighter, and more predictable trigger pull. Unlike an auto sear, these components do not alter the semi-automatic nature of the firearm. Upgraded Bolt Carrier Groups The ATF has ruled that a DIAS is
: Proper training on the use of the firearm with this device is crucial. This might involve professional training sessions or guidance from experienced individuals. Unlike an auto sear, these components do not
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