I have been using Federal SP primers for a fair amount of time and like them. However due to shortages of Fed primers the last time I ordered I got some Winchester primers instead. Used some of the Win primers the other day for the first time and noticed that it takes more pressure to seat the primers than the Federals. In addition, there were a couple of instances when I just couldn't get the Win primers to start in the primer pockets unless I jiggled or slightly turned the case. Are the cases (outter hulls) of Win primers stiffer than Fed primers? Has anyone else experienced this problem? Using a Lee Turret press loading .40 S&W. Wanna kill these ads? We can help!