Sierra has in the past had some inflated numbers for BCs. I can say that the numbers for there current line up is very close today. At least several of the TMKs I shoot myself.I have not. I have read that the twist rate for them is 1:9. However, i personally think that Sierra sometimes exaggerates their bc of their bullets. I have shot the 195 TMKs and also the 195 Hornady ELD M's. The pic attached was from the 195 ELD M's at 300 yrds.View attachment 1127762