OK, Everyone with with a Black scale slipjoint listen up for aging lesson.
Schrade made the Buck 301 and 303 the first few years of production.
They have a S shape, brass rivets on scale, one on each end and the middle spring rivet. The rivets are all the same size. Breath on the bolsters and see if you can see the telltale outline of a blade pin. You WON'T on a Schrade. Don't worry on the tang stamp, look at the above stuff. That only goes for those two models, other models haven't been born yet. Schrade made them good but hard to repair for warranty work. Hence the move of the contract.
So they switched contract to Camillus. Now look at tang it will say Buck, Made in U.S.A. and there will be two rivets on the scale, SMALLER than the middle spring rivet and it will have a model number on reverse. 301, 303, 309 and 305. After that you will see BUCK, model # ( NO date code), U.S.A.. This era is when other models are introduced and different scale materials introduced.
OK, now read close. In 1986 Buck started making there own 301,303,309 and 305s IN HOUSE. And the date code for 86 was < , AFTER this all of those 4 models were coded. NONE of the other different models were date coded until Buck introduced the 312 and 314 trappers and the 310 Whittler.
These "Other Models" 313,311,307, 315,317, etc follow the Made In U.S.A. as earliest version, then Buck, model #, U.S.A. never getting date coded. Even a few never were stamped with a model number, generally those were made special for SMKWs. ONLY BUCK MADE MODELS HAVE DATE CODES. Camillus models were never date coded even till factory shutdown. China made Bucks are date coded.
This date code method does not apply to 110s and 112s till after 1986. Read the chart for those pre 86 110s and 112s...
I have confused you enough....good luck..