Well, if your rifle looks like this:
it was made by Marlin as a Model 99, most likely the 99C. Production started in about 1959, and was one of Marlin's first 22 autoloaders. You did not mention if yours has a serial number- if none, would be between 1959 and 1968 (68 Gun Control Act began to require SNs on rifles and shotguns)
As far as jamming, when was the last time you took it down, cleaned it and lubed it? .22 rimfire is some nasty stuff.