Elevation and power factor

[lvipscshooter]

This is probably poster here somewhere but I have been unable to locate it. What effect does elevation have on PF. I am going to be travelling quite a bit this year to some larger matches (I live in Las Vegas). If I am running 179 PF here (38 SC. Vit 3n38 under a precision delta 124gr HP 1.230 OAL in a Akai open gun with Akai comp and SVI barrel with 3 hybri holes and 4 v ports) should I consider it safe in areas such as TX, Ind, Fla, Nor Cal, Neb.?

Thanks

Edited March 20, 2014 by lvipscshooter

[Hi-Power Jack]

Kevin, if you're at 179 PF, I can't imagine you'd be UNDER 165 anywhere - might be over??

YOUR OAL isn't really 1.13" is it?

[walter hornby]

Kevin I live at about 3000 feet. When I go to Florida I find I get a drop of 3 to 5 in my power factor. I get the same thing if I go to Vancouver or Halifax (west and east coast respectively here in Canada.) When I shoot in St. George or Vegas I get no change in PF. Since I have my load set for 175 PF I do not have any problems with these changes. I would think with your 179 you would find the same thing.

[ralphs]

I live a little further west than Walter and at a slightly higher elevation (3,800). The ranges that I practise at and have used the chrono at are from 2,800 to 4,500 ft. elevation (avg. 3,500).

After going back and forth from the local ranges to various ranges in North America including ranges at sea level, I have determined that I can expect to lose about 1 foot of muzzle velocity per 100 feet of elevation. If I go to sea level I expect to lose about 35 FPS of velocity.

This is an "average" loss. Temperature and atmospheric conditions can also contribute to velocity changes.

p.s. my IPSC Standard/Classic (USPSA Limited/Single Stack)ammunition has a power factor is 179-181 and I have not had a problem meeting IPSC power factor (170) anywhere that I have been.

[lvipscshooter]

Good catch on the typo!!. 1.230!! and thanks for the info guys!

Edited March 20, 2014 by lvipscshooter