A firearm reliability system may include a charging handle insert and a variable bolt weight assembly. Other components of a firearm reliability system may include, but are not limited to, a buffer pressure plug, extractor springs, firing pin springs, one or more firing pins, and bolt buffers. The firearm reliability system may address weaknesses in the common rimfire AR bolt system. Using the firearm reliability system, malfunctions may be essentially eliminated. Each component of the firearm reliability system plays a part and interfaces with the others (i.e., the bolt weight spreads the impact on the buffer into a larger area, while reducing the speed at which the bolt impacts the backplate, which then reduces the energy transferred to the buffer pressure plug and thus the impact with the lower receiver).