The Final Step For A Great Trigger Job
Five weights of reduced power springs allow precise tuning of trigger pulls in all S&W revolvers.
Big Book Catalog, Issue:66, Page:226
New Product Supplement, Issue:533, Page:000
SPECS: Kit 1664: 50 springs, 10 of each weight. Kit 1667: 1 each: 11, 12, 13, 14, and 15 lb. springs. Refill Paks, 10 springs of a single weight.