Best left to someone trained to do this.
Model 909 made from 95-96
100-350 or so
You can get an owner's manual for free at the S&W web site.
906 + 909 + 909 + 909 + 909 + 703 + 602 + 909 + 909 + 904 + 607 + 378 = 9,554
-909
909/1
0.001
136 + 909 = 1045
25% of 909 is 227.25
909/2 = 454.5
0.001
10.1