farmerj wrote:We used m118LR 7.62 ball and M855 ball ammo.
You still claim that temperature will not effect zero.
It does.
As does humidity and if you have a tail or head wind.
As you said, your software gets you on the paper. That's it.
It doesn't dial you in for a first hit cold bore shot.
Hard data only acquired from actual range time provides that.
Reread the post. I have
absolutely stated that temp effects POI. At 200 yards, everything else being the same, a 175gr SMK bullet with a MV of 2603 will impact exactly 0.1" low with a 20* temperature drop. At 1000 yards it will impact just over 11" low. A lighter, faster bullet would be effected less. What I'm saying is that your claims of a 20* temp difference causing a 3" shift of POI at 200 yards is bull$hit. I have never once said that temperature doesn't effect zero.
And when I said that my ballistic calculator gets me on center paper at 1000 yards, that accounts for my shooting skills. It usually takes me several strings behind the gun to get myself dialed in. That is not in any way an inditement on the ability of a ballistic calculator to accurately predict POI, but on my long distance shooting skills, which unfortunately can be rather inconsistent. Science works. Math works. There are shooters that can hit a 12" steel target at 1 mile using nothing but a ballistic calculator, and by anticipating the current MV based on bore conditions, etc.
There simply is no way that a 20* change in air temp can result in a 3" POI shift at 200 yards. If that's what your books say, then your
guess that it was temperature that caused it is wrong.
You gave me the bullet that you used. If you could also provide for me the muzzle velocity, twist rate, zero distance, sight height, station pressure, humidity, target angle, wind conditions, and the two different temperatures you were shooting at, we can put this to rest once and for all by applying the calculations.
Unless you can provide numbers that show otherwise, there's no reason to continue the discussion. Science says you're wrong.