Gary, when the whole Bren 10 thing started I thought the problem with the 10mm was that it had to much recoil for the "Average" cop.
The FBI issued the S&W 1006 uniformly to all agents. Small statured female agents complained about the recoil. Companies responded by reducing the powder charge to 40SW levels. Someone relized there was unused case capacity and cut it down...suddenly the 40 Short & Weak was born.
I've owned 25-30 40SW handguns, and three 10mm. I cannot tell much of a difference shooting 175gr Silvertip Hollow Points through a Glock 20SF as compared to shooting 180gr Hydrashoks through a Glock 23.
I've sold all of my 40SWs because I didn't like the recoil. I know this sounds hypocritical, but consider this...
The 40Sw is typically squeezed into a 9mm package while the 10mm is typically rattling around in a 45Acp package. The larger frame more than makes up the difference in the 10mm's recoil.
