The Model 620 was introduced in 1927 and is a streamlined version of the original 520.
 The safety was initially located inside the trigger housing just like the Model 520 but by 1929 it had been changed to a cross-bolt located behind the trigger.
 The stock was attached by a bolt connecting the receiver and trigger tangs through the grip of the stock.
 Initially the 620 was only offered in 12 gauge but a 16 gauge followed in 1928 and a 20 gauge was introduced in 1930.
The Model 620 was introduced in 1927 and is a streamlined version of the original 520.  The safety was initially located inside the trigger housing just like the Model 520 but by 1929 it had been changed to a cross-bolt located behind the trigger.  The stock was attached by a bolt connecting the receiver and trigger tangs through the grip of the stock.  Initially the 620 was only offered in 12 gauge but a 16 gauge followed in 1928 and a 20 gauge was introduced in 1930.
Stevens Model 520/620