First shot hits

[BUSTINDOGS]

Lets talk about what it actually takes to make first round impacts. Lets assume the shooter has an accurate rifle, all setup and ready to rock and roll. I see a ton of threads on hear about what caliber this and what bullet that, but not enough about what it takes to make a first round hunting situation vital hit.
I will list a few things off, let us see how the list grows, and changes.
#1 Range how far away is the target
#2 wind speed and direction
#3 shot angle
#4 Altitude
#5 barometric pressure
#6 temperature
#7 humidity
lets also talk about the different ways we can gather the information, and how to manage this data, So we can calculate the correction in a timely manner.

 

[snookntarpon]

P.E.A.R.L.
Parallax
Environment (wind, temp, pressure)
Angle
Range
Level

 

[BUSTINDOGS]

LEVEL! very important one

Ok Snook how do you gather and manage that?

 

[snookntarpon]

With my new SIG KILO2400 of course! Does it all.gun)

 

[geo4061]

Does it do spin drift and coriolis effect?

 

[snookntarpon]

Yes. And aerodynamic jump.

 

[ShtrRdy]

Since air movement is the hardest factor to know for your shot it might be good to decide on a cartridge which minimizes wind drift

 

[Greyfox]

For my past several years of hunting at long range, atmospheric conditions, angle, etc. has been largely mastered with my Gunwerks G7 RF. I have recently purchased a Sig 2400 which so far appears equally effective, but I have yet to put it through a hunting season. Much of these aspects have been taken out of the mix with this technology. For certainty of first shot hits on game at long range I have concentrated my efforts on two key aspects.......selection of a solid shooting position, and wind dope. Both are not only critical for a first shot hit, but are typically different with each encounter. While there are tools and aids to help, optimizing them is a matter of practice and experience.

 

[geo4061]

Greyfox you nailed it. Every time you think you have it all worked out WIND jumps up and gives you a lesson.

 

[ColdBoreAccuracyHunting]

When considering position dependent weapon/ammunition/shooter precision and wind, it is the uncertainties that will be the most meaningful. Consider muzzle velocity as an example to follow. An average MV can be recorded using a chronograph but the most important data is the standard deviation. An average MV of 2700, 2800, or 2900 fps for different loads input into most ballistics computers all have the same SD of 0 fps. However, an SD of 60, 40, 20, and 5 fps all have a different meaning to precision. Most ballistics computers can't differentiate between an average MV of 2700 fps with an SD of 80 or an average MV of 2700 fps with an SD of 5.

Now consider wind. Again, a computed wind value of 60, 40, 20, and 5 mph all have the same wind uncertainty of 0. A shooters established wind uncertainty of +-5 mph compared to an established uncertainty of +- 1 mph is an apples to oranges comparison with estimating first shot hits to a target at the same range. The same can be said for position dependent precision.

If uncertainties with precision and wind can be established, how can this data be used to determine an effective range? In other words, the combination of uncertainties in the shooting environment dictates the range where the edges of the estimated uncertainties match the edges of the desired target.

The MRPA will be hosting a free multi-day cold bore accuracy (first shot) hunting class where a group of trainers will instruct how to develop precision and wind uncertainties in a practical field environment and how to use this data to establish a maximum effective range. http://www.longrangehunting.com/forums/f17/cold-bore-accuracy-course-montana-spring-2017-a-176948/

 

[redbullitt]

Good one on keeping the rifle level. Forgotten often I think.

There are are few nice little bubble levels that piggyback on the scope, or my personal choice right on the rail under the scope.

May not be ideal for some setups, but it works really well for mine.

 

[Chopperguy]

P.E.A.R.L.
Parallax
Environment (wind, temp, pressure)
Angle
Range
Level

Like mentioned by another, I'd add an S to the end for

Stable Shooting Position

Great and simple advice here!

 

[CarbonBonds]

This is not a super fast way of attaining first round hits, but Calc Forms can be very useful when learning the process. I use the Calc Forms that Tiborasaurus Rex has posted in his Sniper 101 course; video 78 goes over how to use his version. I can do the math, but learning the wind is my next big task.

 

[BUSTINDOGS]

All very good stuff. For you guys with more experience. Do you find that you get accurate shooting solutions from these devices each and every time you use them? My concern is that I live in the Midwest at 1400' and where I hunt is between 5400' and 8900'. If I know that my system works perfectly at 1400 feet and I take it a thousand miles west and a couple thousand feet higher and the barometer has changed and the air density is different are the calculation that are made by these devices accurate?