When I was a kid the summer camp I went to in 1968 used the bolt version of the 66 for our rifle training. They used the same 10 rifles all summer long shooting about 500 rounds a day for 10 or 11 years when they quit marksmanship training. Just wipe the bore out once a week! NEVER OIL a Nylon 66, the stock will produce all the lubrication you'll ever need. (Oiling WILL cause it to gum up and get jammed!)
The real Nylon 66 was out of production when I wanted one for my sons. But FIE made a very good copy in Brazil. I walked into a going out of business sale in 1985 and bought 3 ($39 each) of these for my boys (ages 6, 4, almost 1) and put the away for their future. They got to have the locked to the wall in their room about 4 years later. Society had changed since I was a kid, In the 60's when you saw a boy walking down the road with a rifle you offered him a ride! If anyone saw a kid with a rifle in the 90's, they called the sheriff! So my kid's rifles were in a locked gun rack until the youngest was 17 (the other son's were in the military at the time, and told me how unfair that the "baby" had unlimited access to his rifle!
Over the decades we have fire tens of thousands of cheep 22's through these rifles and never had a fail to extract. On rifle did develop a fail to feed problem once, it turns an adult non family member was shooting with us and forced a stick down the feed tube (reason, never explained!)and left debris in there, a thorough scrubbing of the feed tube took care of the only problem we ever had!
Ivan