browning .22

Question
trying to find year it was made browning .22 lever action serial number 50561px126

Answer
Hello John.
  Your BL-22, 50561PX126, was manufactured in 1983, by the company Miroku of Japan. I will break down the numbers to explain.
#1. The 50561 is the actual number of manufacture, beginning with 01001 each year.
#2. In 1976, Browning went to a '2 letter' year of manufacture code. Your 'PX' equals 1983.
 Z=1;Y=2;X=3;W=4;V=5;T=6;R=7;P=8;N=9;M=0. This code is still in use, ZV= 2015.  
#3.The two grades; BL 22 Grade I is marked with a '126' model number and the BL 22 Grade II
 number '226'. Your rifle is a Grade I.
#4 In 1976, Browning began having some of their firearms manufactured by Miroku of Japan.
 Other models were still manufactured in the US. The same 3-digit numbers that mark the 'grade' are used to show which company they came from. '126', before the letters date code, means US. After the letter date code means Japan. Your numbers follow the letter date code. Therefore, your Browning was manufactured by Miroku of Japan( a very high quality firearms company, I might add).
   I have enjoyed doing this research. Now, enjoy your Browning BL22 for many years to come. Charles Gage