Can one of you folks tell me why I might like 3f over 2f or vise versa.Been shootinf 2f in KRB w/110gr.Bullets it groups well with are the 250gr Barnes Spit Fires and 250gr.Shock Waves.Consistant 1 to 1 1/4' groups.Just want to know the science behind 3f.Also,use w209 primers.Any need for a different primer w/3f? Thanks...hunt4me