I am working up some 45 super loads for use in my 625-2. Goal is to achive 270pf for the 'norwegian major magnum class' (min 210gr bullet and 270 power factor). I used a 1911 with barsto barrel (grooves 0.005") and a 225 gr self cast bullet, stopping at 1230 fps (12.2 gr vv n105 and 1.275" OAL). This is a accurate and stout load, showing no overpressure signs. When using the load in the 625-2 accuracy goes down drain, giving occational keyholing. When meassuring grooves they show up beeing just 0.003". I suspect this is causing nonstabilized bullets. Q #1 : are 0.003" grooves standard for S&W? Q #2 : will harder bullets (more antimon) cure problem, or must I go ordinary jacketed bullets?