Scopebite65: I used to live near and sight in my Hunting Rifles on the tide flats area of Seattle - the elevation was literally 25 feet or so.
Then I would take my Rifles and go Hunt the very high country of Wyoming, Idaho, Utah and Montana.
Indeed my bullets would fly a tad flatter (1" to 2" higher at 100 yards!) and almost certainly a tad faster there in the thinner air.
So I got into the habit of sighter shots once at altitude.
Notation made and worked with.
The air is only 85% as dense at 6,000' altitude as it is at sea level (zero feet altitude).
I have forgotten the density of air at 10,000' (about as high as I have Hunted big game).
I now live at 5,400" altitude and my Rifle ranges are at 5,900' and 6,000' respectively so those worries are now alleviated for the most part.
Best of luck to you down New Mexico way this fall.
Hold into the wind
VarmintGuy
