At my last range session, I noticed my Model 19 no dash had light primer strikes with certain .38 ammo. In the past, I had this issue with cheap ammo, such as imports or WWB 38s. However this time it happened with such quality loads like .38 Golden Saber and Buffalo Bore. On the other hand, my defense loads(.357 Golden Saber, Federal 357B and 357E, as well as the Remington .38 FBI load) worked fine. The mainspring screw is factory tight. Could this be simply an ammo issue or a problem with the gun? Thanks for any advice.