No, you don't need "special gear", you need dependable gear.
The CAR is a good gun, but the short barrel versions are notorious for double feeds (failure to fully extract the fired case prior to stripping the fresh cartridge). If your 11" barrel CAR doesn't double feed, then you likely haven't shot it much. When, not if, your 11" CAR stops working, you had better be able to rapidly transition to another gun.
Ironically, 16" CARs can be exceptionally reliable. Why? Because they have a longer dwell time. Don't think that a pigtail will solve the problem. Pigtails have their own issues, such as sagging when hot.
The reality of SHTF and other bad situations is that you will already have your hands full without you weapon screwing up. SHTF weapons should evoke words like dependable, durable and reliable.