Shop › GROVTEC HAMMER EXT MODEL 336 MARLIN GROVTEC HAMMER EXT MODEL 336 MARLIN $12.49 GrovTec Hammer Extension, Fits Marlin 36 (1936-1947) and 336 (1948-1956), Black GTHM308 Quantity: Add To Cart Added! GrovTec Hammer Extension, Fits Marlin 36 (1936-1947) and 336 (1948-1956), Black GTHM308