Approximate Silver Weights for each strike are listed in the Comprehensive Nevada Silver Strike Reference Catalog.
You can purchase this Catalog from: Warren Schaefer, SS-185 at email@example.com or through eBay Seller ID: wschaef86.
Most Silver Strikers and I have used this dependable and informative William Cohenour Strike Guide for many years.
I hope this info helps,
eBay Seller ID: dal166322