Hi:
I was at the range yesterday with several S&W "K" Frame .38 Revolvers.
Shooting a new 50 round box of Remington 158 Grain LSWC-HP +P ammo.
Two rounds wound not allow the cylinder to turn. The two rounds would seat full length in the chambers but still would not allow the cylinder to turn. I checked for high primers, but the primers were fully seated.
It appeared that the cartridge rims were a mite too thick.
I tried the two cartridges in different "K" Frames revolvers with the same results.

In "The Day" after the revolvers were loaded, it was a practice to close the cylinder, pull the hammer part way back, and spin the cylinder. I am considering starting this practice again.

Quality control at the ammo factories has "Slipped" somewhat.