When was the Remington model 6 serial 412575 made?

The model 6 was made from 1901 to 1928 and that's a fairly late serial no, they made approximately 450,000 before the improved model in 1929 started. Since it's a later one it should be date coded on the barrel left side in front of receiver a diagram and chart can be found on the Remington Society of America's (Collector Site) here: http://remingtonsociety.com/rsa/questions/barrelcodes