People who carry 40S&W

[PHATSPEED7x]

Wild.I didn't know.I wonder if other polymer pistols (XD's,M&P's,etc) do the same thing?

S&W and XD pistols have a more solid take down lever that needs to be rotated. Don't think that would become disengaged while firing.

[UnaStamus]

Wild.I didn't know.I wonder if other polymer pistols (XD's,M&P's,etc) do the same thing?

I don't know about the XD, but there is minimal frame flex in the M&P. The M&P was actually designed around the .40S&W cartridge, and it was designed to correct the WML malfunction problem that the Gen3 Glock 22 was prone to. S&W inserted a steel chassis into the polymer to nullify frame flex as a recoil control property so that it can't be negatively affected by a disruption in frame flex harmonics when a WML is attached.