I know the whole thing over 10mm and, 40 S&W has been beaten to death but, I recently handled a Glock 29. I am used to wider gripped guns and, currently shoot the heck out of a Ruger P91DC in 40 S&W and, it does well. I have a military background and, know that the govt. use of this round prooved that it over penetrated and, there has been much to do over rounds being lightened up to curb this. I have had folks try to steer me away from this caliber as most places don't carry much in ammo and, the selection of guns as far as frames go is limited. I am looking for opinions from folks who shoot this caliber and--PLEASE--I am not trying to get a war started over one caliber verses another. Why is it that this caliber has just not taken off??? Seems that all I hear is about 9mm, 40 S&W, and, 45 ACP. Just no talk much about the 10mm--Why is that???????????