Kits & individual Springs To Improve Functioning
M77 Mark II kit contains (1) extra power, 24 lb. Blitzschnell striker spring and a reduced power trigger/sear spring.
Reduced power trigger/sear spring fits 77/22 models chambered only in .17 HMR, .17 Mach, .22 LR, .22 WMR and the 77/44. The reduced power trigger/sear spring also fits Ruger 77 MKII centerfire models EXCEPT for target models and Hawkeye series. Not for use in dicontinued Model 77.
Big Book Catalog, Issue:70, Page:181