Air Temperature Effects On Muzzle Velocity By Gustavo F. Ruiz

[yobuck]

well im not offended by that as i know your intentions are good. just somewhat misguided as far as longrange hunting goes.
needless to say one should strive to be the best they can be in any venture including the subject matter.
that said there are things beyond our control we can only cope with and adjust to as best we can.

i come from a state where long range hunting and 1000 yd. target shooting as we know it were born. that being pennsylvania.
ive known and hunted with some of the best long range target shooters the world has known. also some of the best gunsmiths for building those type rifles the world has known.
my association with long range hunting goes back over 40 years.

1000 yd. target shooters wouldnt even think of firing their record group without taking sighter shots.
even then conditions can change in an instant, causing the very best shooters serious problems.
yet come hunting season when most guys leave their rifles and ammo in the vehicle on below freezing nights, were somehow expected to make first shot kills on game.

obviously youve never experienced those wide valleys where the wind can blow in several directions at the same time. sometimes straight up off a frozen river below.
your fingers might be so numb from waiting for a shot you cant feel the trigger.
the opposite sidehill is also tree covered and that means branches, lots of branches.

the best hitters in baseball still get 3 swings of their bat. when they connect on the third after missing 2 everybody celebrates.
and you know what, so do we.
you can think whatever you like about that.

 

[Pdvdh]

When the target is a living game animal, some think it best to put in the effort to help ensure first round hits in the vitals. That's what the topic of this thread is intended to do. Testing MV at a few differing equipment temperatures to determine whether or not MV changes should be considered, and modified in a ballistics program, to allow for their affect on POI at long range.

One of your prior posts talked about employing a spotter to bring second or later shots on target. Nothing wrong with that. However your posts seemed to under-emphasize preparations to improve first round deadly hits. And over-emphasize follow-up shots. That's my take on it, and why you're getting some guff.

 

[Mikecr]

I'm born & raised in NE PA.
And I have not, and never would assume multi-shots to take game.
The hook to HUNTING is strategy, and all other preparation efforts paying off, to overcome the challenges of it.
It isn't just steping away from the truck and shooting and shooting far off -until hitting something.
Even target shooting is not so pathetic...

I'm from PA, and I do not shoot beyond my single cold-barrel-shot capabilities.
Yes, I miss, and so my mark lives another day..
Now my passion is again charged!

Friend, correlating anything in hunting to target shooting, and stretching with this only to reduce your efforts, will only chip away your character, and cheapen this sport.

 

[yobuck]

pharworth, you are absolutly correct in your assesment of the importance of first round hits in the vitals.
certainly that should be strived for to the best of our ability.
if my prior remarks led you or others to think i consider that unimportant, i appologise for that.
that certainly isnt what i think or would encourage.
i do think its dangerous to promote the idea that with proper equiptment and training, mistakes cant happen.
im of the opinion that the read it, dial it ,and then just one shot theory is just that, theory.
there is no doubt cold weather affects velocity, and that can vary according to powder used. if some want to go to great legnths to try and figure out how much affect it has thats fine with me.
ill repeat what ive said in other post. if you want to be a successful and consientious long range hunter use a spotter.
as for the comments about target shooting and long range hunting having no correlation. well thats too assenine to even comment on.

 

[Mikecr]

im of the opinion that the read it, dial it ,and then just one shot theory is just that, theory.

You need to listen to those who do just this.
Being a successful long range hunter is like being a successful sniper. You stalk your mark at distance, and drop it with an intelligent, high percentage shot.

I hit 500yd chucks with single shots at better than 80% with a 223.
Why only 500?
Because that's where I can hit them with such a percentage -in the field.
Is it 'long range hunting'?
Yes.
Is it long range shooting?
Who cares??

There are no sighters.. No walking shots into game.. No shooting and shooting till you hit.. It's not a friggin video game......
For any situation where you're not certain about the shot, move to a better position for a shot.
Could be closer, could be further. What should matter is that you know what you're doing, and you get-r-done..
If you can't get a higher percentage shot, you just don't shoot.

Why would you shoot anyway?
Because you just don't get it.
And you will never be a long range hunter...

 

[Chas1]

Good article but I must admit I have read it several times and understand it a little better each time....I think. Thanks for sharing your knowledge.

 

[yobuck]

not all that many years ago this conversation wouldnt have taken place. thats because very few people in very few places were doing what were talking about here.
back in the 50s for example very few hunters even had scopes on their rifles.
the most popular rifle by far in the pa. deer woods at that time was a 3030 model 94 winchester.
yet even then, there were guys doing what were talking about here in the steep mountains of n/c pa. and quite possibly other places as well.
they took alot of flak also. again, mostly from other hunters.
my first awareness of them was in 1956 when i witnessed a man laying prone on a dirt road kill a deer with a 270 with a unertle scope on it. he claimed the deer was 700 yards.
years later i checked that distance with my newly aquired barr&stroud rangefinder. he was almost exactly right on .
the improvments in knowledge and equiptment since then is hard to comprehend. most of those improvments at least on the equiptment end, can be attributed to the shooting community, not hunters.
for what its worth, im not and have never been a serious target shooter.


as for snipers, the only similarity between hunters and snipers is long shooting.
the sniper has his life on the line, and quite possibly the lives of others.
a miss could mean disaster for them. its certainly in his best interest to get any advantage he can.
thats not the case in hunting however.
this is what we choose to do for enjoyment. our lives are usualy not in danger, only our egos can be injured.
certainly we should strive to take game in as humane a manor as we can. every consideration should be taken before we decide to pull that trigger.
but all that considered, i for one think its ok if you happen to miss.
if he wants to stand there and let you try again go for it.
hopefully through the eyes of your spotter you'll know why you missed and the next shot will bring different results.
shooting at animals across valleys, standing on steep sidehills is a different game than shooting at them on the other side of a meadow or across a ravine.
for us, 500 yards is a very nice shot, but its not what we think of as long range.
sorry about that.

 

[TexasHunter]

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

 

[Pdvdh]

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.

 

[Eaglet]

+1

Thanks for sharing!

 

[CRaTxn]

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

 

[Mikecr]

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...

 

[CRaTxn]

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 ?

 

[Mikecr]

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.