When people wonder about effective range, the real question is how good of a shot are you with the current load. If you can get that rifle to group at 150 yards, there is no reason not to try a shot if you can place it. What I hate to see are those people that "just want to get some lead in them." 100 grains with that powerbelt should work real well for you out to 150 yards, although there are a lot of bad posts about the effectiveness of powerbelts. Some people love them, some hate them.