I was going through my SIERRA loading Manual and noticed the hunting load for the 7WSM was H4350 EXT what does EXT meen? I noticed on another load in the 7MAG 160gr for a hunting load H4831 SC at the end? I have never payed any attention to this, its been bugging me for a long time. I don't wish to sound like a dummy. I think it does sound like Iam one.