Rainy afternoon so spent a pleasant hour or so at the Mec 600jnr. Loaded 60 game shells and each of them was a work of art...even with a substitute primer. Belatedly found the data sheet and there is an amazing 3gr powder difference with the new primer...all those beautiful shells are 2gr over maximum listed load. Learn from my mistake and check data BEFORE substituting components. Kind Regards-Graham.