US Patent 10982921 Firearm barrel pre-loading devices, connection assemblies, and firearms

A firearm barrel preloading device can preload threaded connections. The preloading device can include an outwardly facing barrel-contact surface, an outwardly facing receiver-contact surface, non-planar surfaces between the barrel-contact surface and the receiver-contact surface. The non-planar surfaces can include mated pairs of axisymmetric surfaces that cooperate to spread apart the barrel-contact surface and the receiver-contact surface when the preloading device is moved toward an expanded configuration.