Cold weather POI question

scout1775

Private
Minuteman
Mar 17, 2013
8
0
I went shooting when temp was around 45 degrees. I'm shooting a 700 sps, leu MK4 glass, B/C stock ...blah blah blah. Here in FL I usual shoot in temps around 70-80 so 45 is cold for us. My first shot I expected to be high with the lower temp but it was complete opposite. POI was about 1 1/2 - 2 in below POA. Am I wrong? Does cooler weather not make the POI higher? What would cause the lower POI?

Cold weather BOOT
 

Bear24

Sergeant
Full Member
Minuteman
Oct 27, 2012
605
96
Oklahoma
Are you shooting factory ammo or reloads? If reloading, what powder are you using?
 

roggom

Senior Chief
Supporter
Full Member
Minuteman
Mar 29, 2011
2,628
83
Northern Colorado
Yah got it backward, lower temp = Lower DA (density altitude) = lower POI.

That said, 45 degrees is not considered cold enough to be that far off unless you are shooting way out there, and / or you are using a single based powder.
 

Bear24

Sergeant
Full Member
Minuteman
Oct 27, 2012
605
96
Oklahoma
My guess with the colder, more dense air and getting a little less velocity because of powder temp is the reason. I'm sure someone will chime in with a better answer though.
 

B3dlam

Sergeant
Full Member
Minuteman
Jan 3, 2012
754
4
Kodiak, AK
Colder temperature equals denser air and therefore lower bullet impact. Just running the Ballistic calculator for 168 FGMM at 500 yards you get 59" drop at 45 degrees and 57.8" at 75 degrees. The drop isnt significant but its a basic idea for you.