Ruger introduced their east-takedown PC (“Pistol Caliber”) Carbine in 2018 as kind of a follow-up to its old PC-9/PC-40 Police Carbine of the 1990s. In its basic format, it weighs 6.8 pounds.
In its AR Chassis format, which was introduced in 2019, the weight went up to 7.3 pounds. Notably, as Magpul tends to do, they introduced a fix to the Ruger PC late last year in the form of a Backpacker stock that both shaved weight down to 6.2-pounds and allowed for easy stowage in a backpack– hence the name.