Max effective range?

[cmorsch]

How do you figure out what your max effective hunting range is? Do I base this off of velocity at point of impact or retained energy at point of impact?

 

[WildRose]

Lots of factors are involved, none more important than your ability to put it where it needs to be and a bullet that will perform on impact.

Velocity/energy give you a good range to work with but they rarely set the limits.

Think about it, what is required to shoot through both shoulders of an Elk at a given range is far different from what is required to lay it in just behind the foreleg to punch through the rib cage, heart, and lungs. It also really doesn't matter what a bullet does on impact if it takes out the heart and collapses the lungs.

Shot placement is by far the biggest limiting factor.

 

[MMERSS]

Generally, combined precision + accuracy estimates should be less than or equal to target vital size assuming you have sufficient impact velocity and energy to finish the job. How you determine your precision and accuracy uncertainty is explained in great detail in Applied Ballistics Accuracy and Precision for the Long Range Shooting. Buy the book it's worth reading. Determining your maximum effective range can additionally be estimated by practicing many rounds down range in various weather conditions against a vital sized target. Just my $.02.

 

[Canadian Bushman]

How you determine your precision and accuracy uncertainty is explained in great detail in Applied Ballistics Accuracy and Precision for the Long Range Shooting. Buy the book it's worth reading.

+1.

 

[cmorsch]

Ok, I forgot to say max range based on what cartridge you are shooting.

 

[WildRose]

Ok, I forgot to say max range based on what cartridge you are shooting.

Again, for any given cartridge that is going to depend on a great many variables from the shooters ability to hit the target in the desired place to the type of bullet, it's BC, and the velocity/energy needed to penetrate and kill the intended animal.

Number one is bullet placement because if you cannot hit the target in the vitals the rest of the variables don't matter.

The kill zone on most medium and large game is going to be between 12-18" high and 2-3" wide if your aimpoint is the shoulder. The maximum possible range for any weapon then will be the the longest range at which you can consistently place the bullet in that zone.

You can go from there looking at various calibers and types of bullets to narrow it down even farther.

 

[kcebcj]

How do you figure out what your max effective hunting range is? Do I base this off of velocity at point of impact or retained energy at point of impact?

I think the accepted normal of ft. lbs. of energy for elk size game is 1500 and 1000 for deer size game. The bullet manufacture of choice will list the minimum fps for proper bullet expansion. So once you have a load and have proved the velocity or use the advertised velocity on store bought shells which is iffy you can take those numbers along with the bullets BC and run them in a ballistic program to find the yardage at which whatever you are using will perform properly. Of course if you are shooting at varmints the energy level is quite low and pretty much comes down to whether or not you can hit them at distance.


There are other variables to consider as stated in other post but if you have the maximum yardage in which everything performs properly and stay within those limits you are good to go. Of course all is cartridge dependent

 

[Greyfox]

How do you figure out what your max effective hunting range is? Do I base this off of velocity at point of impact or retained energy at point of impact?

By asking the question as "your max effective range", it sounds like you are asking in terms of a "specific" individuals maximum hunting range with their rifle and capabilities. Not sure it's the best approach, but I go through the following process:
-What is the animal(s) I plan to shoot and what is the minimum energy required, and vital zone area to kill it.
-Determine the required minimum velocity of the bullet/load, and resultant maximum range that the bullet/load has the properties to effectively kill the target game. I will also take into consideration the environmental conditions(altitude, temp,etc) that effect the velocity requirement.
-I will adjust that maximum range(lower), if necessary, to align my accuracy capability under optimum conditions, to the animals vital area. This is my max range.
-Finally, for any given shot at an animal, the actual range I will shoot will be determined by my ability to hit the vital zone for that specific shots environmental conditions (wind, atmospheric, shooting rest,etc) and not exceeding max range.

 

[Kennibear]

All of the posts prior to mine are excellent. But maybe you can apply a 'design spiral' to come to your conclusion.
1) Make some basic assumptions. I can shoot this far accurately, etc.
2) Determine the minimum energy level you are comfortable with.
3) Determine the lowest velocity of reliable expansion of the selected bullet.
4) Determine the lowest velocity that the selected bullet retains your energy threshold.
5) Your maximum range is the yardage that the velocity drops below either #3 or #4 above, which ever is higher.

KB