I am using the Point Blank Ballistic program to calculate the ballistics for my 308 win. With the conditions I'm shooting under then the program says I need 38 moa to be zeroed @ 1000 yards from my 100 yard zero. But I actually need 42.5 moa. Is this amount of error typical of Ballistic programs? Here's my data if someone would please verify it on another program for me: 175 grain Matchking BC=.496 Velocity is 2640-50 fps elevation is 5000 ft above sea level temperature is 90 degrees scope height is 1.5 inches The reason I am asking is because I was rereading Blaine Fields post "Why a Knowledge of Ballistics" where his 1 in 12 twist barrel was having issues with the heavier projectiles at 1000 yards. I was able to consistantly hit at 1000 yards so I don't think my 1 in 12 barrel is having problems, but I thought I'd ask anyway.