never had a 300 win mag before but iv had variouse 30 cals before includeing a 308 norma mag,i also have a 7mm rem mag,i think its a personal choice but i love the 7mm,i decided to buy a 7mm over the 300 mag simple just to try something new,and im not disapointed one bit.i am not coninvinced the 300 mag will kill any better than a 7mm mag.like someone posted previousely,id stick with what you got since you know how it performs already.id never dream of tradeing mine off,id just keep it and buy a 300 mag.if it aint broken why fix it?