I have finally decided (i think) on a scope for my 7mm rem mag but am looking for opinions on power range. im going to order the Vortex Viper PST and am set on the based off cost and what i am looking for in a scope but cant decided between the 6-24x50 or the 4-16x50. i have an area where i can shoot up to 1500yds. any input would be appreciated.