the old TARGET load used to be 168 grain sierra smk, 43.9-44 grains of ww748, and a cci lrge rifle magnum primer- i dropped back to 42, used a remmy core-loct that i get in BULK, ( 165) and worked my way up to reliability at about 43.5-43.9- 44 .1 started to show flattened primers- it's WELL DOCUMENTED- ALL YOU HAVE TO DO IS LOOK UP M14 TARGET LOADS by zediker- it's on the net- br2 or milspec primers are NOT NECESSARY and a MARKETING GIMMICK as far as the m14 is concerned