Kragman1: I have had several friends with Marlin Model 60's - and I have shot most all of their Rifles along with them.
One of these was a very early Model 60 (they were introduced in 1960 in fact!) and I think it was about 1962 when we (the young 15'ish me!) and my friend were out plinking with our 22's one summer afternoon.
About mid-shooting session his Marlin Model 60 went "full auto" on us - emptying the tubular magazine completely and just about instantly!
It turns out his older brother had been trying to "modify" the Model 60 into being a full automatic Rifle!
The rumor was back then when the Model 60 was "new" that they could be modified into "full-auto" easily and lots of curious (dumb) types were trying to attain this condition!
It was cool this "full auto" feature - but sadly had this major drawback (at least on his gun!) you could get it to fire "full-auto" but you could not stop the "full-auto" once it started rolling!
It ate ammo FAST!
So he had to single load the Rifle to get it to a manageable rate of fire.
Eventually a "parent" got involved with the Rifle and it "went away".
Be aware of this around the real old, early Model 60's - they may have been tinkered upon.
Again back to the rumor mill - it was "rumored" that the folks at Marlin soon implemented a change that prevented "full -auto" firing modifications.
Before that "modified" Rifle of my friends "went away" we tried to "time" how long it took for it to empty the tubular magazine - IIRC it took less than three seconds.
Fun but not safe or useful for plinking boys/young Hunters.
Enjoy your nifty Rifle.
Hold into the wind
VarmintGuy