I have 3 Winchester model 43s. The first one is in 25-20 ser # 65xx.(1949) The second one is in 218 Bee ser # 31xxxA.(1950) The third one is in 22 Hornet ser # 14xxx.(1950) None of these are drilled. I firmly believe Pocono Jack is correct.
He is absolutely right and that change occurs between serial number 31,000 and 32,000
