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Air Temperature Effects On Muzzle Velocity By Gustavo F. Ruiz

 
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  #22  
Old 08-14-2010, 02:23 AM
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Re: Air Temperature Effects On Muzzle Velocity By Gustavo F. Ruiz

Guys,

I'm new to this forum and can easily appreciate the several points being made here. If we all are about long range hunting, then we must strive to be as "ethical" as possible with regards to first round deadly hits and not wounds. What I've learned over the years hunting in TX on hunting leases with many different lease partners is that what one considers long is short for another and vice versa. We should all strive to both stay within our own ability for the shot on game animals as well as strive to extend our ability through as much pre season practice as possible and the pursuit of the best tools we can build or buy. We build the finest rifles we can, we buy the finest optics for our rifles and for determining range, we spend hours/days /weeks perfecting our reloading procedures and tuning our ammo to the gun, we compete at long range as often as possible, we use spotters and target pullers/pasters to give us immediate feedback so we can assimilate as much shooting knowledge as rapidly as possible and in my opinion, we need the best ballistics software predictions we can get because as many have pointed out, when it's oh-dark-thirty and we are by ourselves on a hillside or in a blind we need to know with as much certainty as possible what will work with the highest odds possible for the first and most likely the only shot at Muy Grande. The more intelligently I can model my equipment's performance under widely varying conditions = the better. I regularly set up at 650 yds on whitetail doe across a valley from hillside to hillside on a easterly heading. In central TX it can be mid 20s F in the morning and mid 60s F the same afternoon. And my dope is always enough different that without practice and predictability it would be an impossible shot. Up to now, I've kept pretty decent data for this shot as well as many others in competition and I've yet to have the ballistic calculators agree with reality past 400 - 500 yds. So I'm always looking for software that assimilates more and more variables. I bought Loadbase last week and immediately started testing it against as much historical data as possible and I have to say that so far it is showing substantially greater correlation to reality out to 1000 yds than any of the other half dozen or so programs I've tried. If logging MV vs Temp will give me additional insight, then i'm all for it because I know with certainty that rifle and ammo at 28degrees perform differently than at 90 degrees.

Best wishes to all
Dale Troutt
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  #23  
Old 08-14-2010, 05:54 PM
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Re: Air Temperature Effects On Muzzle Velocity By Gustavo F. Ruiz

Quote:
Originally Posted by TexasHunter View Post
Guys,

I bought LoadBase last week and immediately started testing it against as much historical data as possible and I have to say that so far it is showing substantially greater correlation to reality out to 1000 yds than any of the other half dozen or so programs I've tried. If logging MV vs Temp will give me additional insight, then I'm all for it because I know with certainty that rifle and ammo at 28 degrees perform differently than at 90 degrees.

Best wishes to all
Dale Troutt
Thanks for sharing your initial experiences with LoadBase 3.0 while running your historical data through the software.
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  #24  
Old 08-14-2010, 11:07 PM
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Re: Air Temperature Effects On Muzzle Velocity By Gustavo F. Ruiz

+1

Thanks for sharing!
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  #25  
Old 11-13-2010, 12:04 PM
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Re: Air Temperature Effects On Muzzle Velocity By Gustavo F. Ruiz

For a lot of us hunters changes in temp come in concert with changes in altitude. i.e. I just returned to TX & 650' PA (Pressure Altitude not Pennsylvania) from 7,800' PA in AZ (Arizona) on a mule deer hunt. My capabilities and wind reading skills or lack there of restrict me to say 950 yards , so I may not be what some more advanced readers will call a true LRHr. In flying we use the rule of thumb that the standard adiabatic lapse rate is 2*C/1M'. I note that Aaron Davidson and the Huskemaw bunch make turrets that must accomodate these variables for real world "intermediate" long range real time hunting solutions. They might pair a 2M'/50*F turret with a 7M'/30*F turret for one of their scopes to take care of the pratical situations for "MOST" hunters. I am sure they have shared these rules of thumb with this blog before but think the administrator thru his connections with Huskemaw as a dealer might shed some light on this argument by reiterating Aaron's rules of thumb and telling us what turrets he has for his Huskemaw scoped rifles!? WHAT I AM GETTING AT IS THIS: THERE IS A CANCELING EFFECT IN THAT LOSSES OF MV DUE TO LOWER TEMP ARE SOMEWHAT BALANCED BY FLATTER TRAJECTORY DUE TO HIGHER DENSITY ALTITUDE OR PRESSURE ALTITUDE (PA).
Wish we had a pilot's whiz wheel for performance in shooting like we have for flying...the batteries on my electronics don't seem to like those cold mornings in hunting camp.
Somewhere Between Ignorance & Arrogance in TX,
CR
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  #26  
Old 11-13-2010, 07:04 PM
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Re: Air Temperature Effects On Muzzle Velocity By Gustavo F. Ruiz

Quote:
Originally Posted by CRaTxn View Post
WHAT I AM GETTING AT IS THIS: THERE IS A CANCELING EFFECT IN THAT LOSSES OF MV DUE TO LOWER TEMP ARE SOMEWHAT BALANCED BY FLATTER TRAJECTORY DUE TO HIGHER DENSITY ALTITUDE OR PRESSURE ALTITUDE (PA)
You just got all that completely wrong...
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  #27  
Old 11-13-2010, 11:21 PM
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Re: Air Temperature Effects On Muzzle Velocity By Gustavo F. Ruiz

Crap I thought the higher the temp the greater the MV.
I also thought the higher the PA or less air density the less drag and higher the BC.
Are those wrong ?
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  #28  
Old 11-14-2010, 09:35 AM
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Re: Air Temperature Effects On Muzzle Velocity By Gustavo F. Ruiz

I probably took your reply out of context,,
It implied to me a notion that cooler temps meant lower(countering) air density -as correlated with 'standard atmosphere' temps at higher pseudo-altitudes(not actual), which are listed as lower in air density.
But the truth is temperatures have nothing at all to do with altitude. In fact altitude, is NOT a ballistic term. Pressure, Temperature, and Humidity all vary irregardless of it.

Unless Huskemaw has diversified into air density measurement riflescopes, they should probably stay away from weak suppliments of it.
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