... as it is possilbe to achieve with rotary core drilling equipment. It is not uncommon for drillers to report 98% + core ... recovery in the most difficult formations.Size available:Q series Core Barresls: AQ, BQ, NQ, HQ, PQ, NQ3, HQ3T ... series Core Barrels: T2-56, T2-66, T2-76,T2-86, ...