.22's
Wiki says the Rem Nylon 66 rifle was last made in 1989, that seems a bit late to me, I thought they'd departed prior, maybe Wiki is including clones which seemed to have surfaced at some point in time as well.
I'm .22 rifle poor, but the one I shoot the most is a Ruger 77/22 stainless, synthetic (boat paddle stock) It wears a Leupold rimfire 2-7x scope and shoots Remington Golden Bullet bulk HP well enough that I have not searched much for another cartridge. It rode in the back of a patrol rig for a decade with no particular special care other than an occassional wiped down and pull through. There was a period of time when I tried to shoot it daily, 10 rds around supper time every evening. The rifle got a Volquartzen sear early on, other than that no other work. It has fired and cycled flawlessly for over 20 years with simple maintenance. I think that little rifle may be the best gun money I ever spent!