9mm Major velocity chg due to altitude

[Big Rat]

I have a slot to shoot in the Nationals (Open) in Vegas. My question is there any significant change in velocity due to the difference in relative elevations? At Area 5 this year, a shooter from California made major PF at home; however, here (IL) he made 164.9. I would appreciate any guidance offered.

[Mitch Harrington]

It has been my experience there is little to no change. Last year, my chrono readings between OK, CO and LV were within one power factor.

[noypi916]

My experience is my PF at NorCal before going to 2010 Limited Nats is 171 PF. However when I got in to chrono stage. It drop by 2 1/2 points to 168.5 PF. I'm still happy since it still made major. That is n320 powder on a CZ75 TS gun.

[Big Rat]

Thanks for the input. I run 121 Mg at a PF of 173 and had a PF of 174 at Area 5. I just wanted to make sure that I would be OK out west. Thanks again for the input.

[RH45]

Thanks for the input. I run 121 Mg at a PF of 173 and had a PF of 174 at Area 5. I just wanted to make sure that I would be OK out west. Thanks again for the input.

What powder are you using? Some are temp sensitive.

Even though it's been pretty hot around here, I'd expect it to be over 100 out there.

[Big Rat]

Thanks for the input. I run 121 Mg at a PF of 173 and had a PF of 174 at Area 5. I just wanted to make sure that I would be OK out west. Thanks again for the input.

What powder are you using? Some are temp sensitive.

Even though it's been pretty hot around here, I'd expect it to be over 100 out there.

I am using Autocomp 7.4 grains, OL 1.170 in an STI GM.