Slim One thing out of the many things Hap knows is proper heat treating of parts, Ole Wild Bills got a couple of years on his.The main springs have been replaced with Wolff s that have been lightened even more,the originals have been placed along with the hand and spring assy. with the C&B cylinders. I really do not plan on using them as C&B s ,just got real tired of waiting on the type II s Ive had on order over a year,I really perfer 51 Navys anyway. I will keep everone informed with longevity and performance,long term. Adios Sgt. Jake