I have searched for info on a few questions and came up with half the answers so I will ask it here in hopes some one can fill in the blanks or straighten me out. 1st question - effect of temperature on POI, I know this is gonna be a lil different for every bullet/gun etc. But is their a general rule of thumb for rough estimation to start with? 1 guy on another site said he loses 1 moa @ 1,000 yd for every 10* decrease in temp? Is that a good estimate? What about 500 yds? Mainly looking for like 40*F - 100*F any colder then that I am on the couch! 2nd question - Wind drift, I know you can use the ballistics programs to get this if you have all your bullet info, I seen on another site you square it, say if your off 1" @ 100yds with a 10 mph crosswind it would be 100" @ 1,000 yds (rough estimate)? 3rd question - barometric pressure effect. I have spent alot of time reading about rain/temp/altitude/pressure tonight, the altitude's I will be shooting at are quite different so that will be easy to dope, what about pressure? Is their a rule of thumb for adjusting? Just looking for some starter info to know where to start. Thanks for any help to get me started.