I don't doubt it! I was simply questioning whether the extra penetration was needed and worth the risk in DRs. I have not used GS Customs, and I'll have to take your word that they could be safely used in a DR. I have used other monos (Goodnel and Barnes) and FMJs in .458Win bolt rifles, and I can't fault the performance. However, I have only shot Woodleigh FMJs in a DR .500/.465, also with faultless performance. Do I need the extra penetration of a mono? When I shoot an elephant, I'll let you know! I think that more elephant have been shot with FMJs than monos though...