Apparatus and associated methods relate to a firearm lock configured to release a self-hardening interlock fluid into a firing chamber of a firearm in response to a predetermined force. In an illustrative example, the firearm lock may include an engagement module configured to releasably couple to a firing chamber of the firearm. In a locked mode, for example, the engagement module may prevent the firearm from firing. The firearm lock may include, for example, a tamper interlock module containing interlock material (IM) in a fluid state. When a predetermined force is applied to the tamper interlock module, for example, the IM may be dispensed from the cavity into the firing chamber and the IM may at least partially transition into a solid state such that the IM prevents the firearm from firing. Various embodiments may advantageously disable a locked firearm in response to tampering with the lock.