Long Range Hunting Cartridge Comparator User Guide

My name is Chris Hague and I am an Architect with a passion for target shooting, hunting, and inventing (check out our products). I wrote this tool because I was searching for some scientific comparison between cartridges to help me choose a chambering for my first custom hunting rifle and found that none of the cartridge comparators available used real down-range ballistics to compare multiple cartridges’ capabilities.

This comparator may be daunting at first glance, but I believe it does what it was created to do: scientifically provide an apples-to-apples comparison of the down-range capability of all common cartridge & bullet-weight combinations against a specific task.

Quick Guide:

Inputs and Outputs:

     Input your criteria into the dropdown menus, and submit. The multi-line plot and columned outputs display the same information in different ways: the downrange impact energy vs. recoil of every common cartridge & bullet combination that can ballistically perform your input criteria at range.

• Each line represents the downrange impact energy and felt recoil range of a particular cartridge and bullet weight combination from lowest to highest muzzle velocity achievable in the reloading manual. Box ammo will most likely be closest to maximum safe load, see columned output for Impact Energy & Recoil at Max Load. 
• Only cartridges that can achieve your minimum impact energy at your maximum effective range within muzzle velocity range of the cartridge are shown, so an example input for Mule Deer such as 1250 ft*lbs of impact energy at 300 yards will NOT show 300 Winchester Magnum since it is overpowered for this application.

Interpretation:

     Review the data and choose a cartridge & bullet weight class that meets your criteria. If you are unsure of the results, or are looking for a particular result, consider the following:

• Increasing rifle weight to reduce recoil, or use our water bottle hosted Arca adapter to use the weight you already lug around.
• Increasing the barrel length to get more performance out of a particular cartridge.
• Getting a better muzzle brake to reduce recoil without changing cartridge, barrel length, or rifle weight.
• If there are too many cartridges plotted, try narrowing the search by choosing an action length, decreasing shootable recoil, or raising the minimum sectional density.

Assumptions to Keep in Mind:

1. All of the data for muzzle velocity and recoil for cartridge and bullet weight-class combinations have been taken from commercially available and reliable reloading manuals and or have been calculated directly from those. Be safe. Some of the bullet weight and cartridge combinations are only available if you hand load ammunition and/or have a custom chamber geometry and twist rate. Email us if you would like us to chamber a custom barrel for you.
2. Lethality is not determined by a single data point, rather it is made up of a balance of shot placement, impact energy, sectional density, bullet diameter and bullet expansion (a consequence of the particular bullet’s construction and the velocity of the impact). The outputs from this comparison, or any other comparator, cannot take into consideration all of these factors; you must do your part and use your best judgment in the field.
3. There are no ballistics equations that use down-range impact characteristics as the primary input to compute required muzzle velocity, so I reversed a well-known set of ballistics calculations to achieve this. These calculations are nearly perfect when put up against other ballistic solvers (JBM and 4DOF), and have been proven more than good enough for this apples-apples comparison; almost all of the error in these calculations stems from using the G1 BC instead of the G7 ballistic coefficients.
4. All the bullets used in this comparator are modern High-BC hunting bullets from Hornady, Berger, and Nosler, since these are the bullets being used most by long range hunters. At this time, there are no solid copper bullets, since they tend to have less efficient ballistics and would skew the capability of the Bullet Weight classes down.
5. Barrel length in centerfire cartridges affects muzzle velocity; SAAMI and reloading manuals (such as Nosler) publish the barrel length that the velocities were measured at for each cartridge. For each inch of difference in barrel length between the standard and your input choice, there is approximately a 25 foot per second velocity change. This is an approximation, your rifle may be different, but for the sake of argument, this is close enough.
6. Lastly, no cartridges are more accurate than others, within reason. Some cartridges lend themselves to more forgiving accuracy, but shooter ability, rifle quality, and ammunition quality all have much greater impact, pun intended.

Standard Inputs:

Your Maximum Effective Range: 

The distance you are comfortable dispatching game in 50 yard increments. There is little point having a cartridge that performs the task further than you can comfortably shoot accurately.

Your Minimum Impact Energy: 

The least energy you think is needed to ethically dispatch your quarry at your maximum effective range. For Rocky Mountain Bull Elk, most folks use 1500 ft*lbs, but I prefer a bit more from experience, something like +/-1750 ft*lbs. This is personal preference, be smart.

Your Rifle Weight: 

This is to calculate estimated recoil. This input can describe your own rifle, a future build, or to estimate the recoil of something you have shot before.

Your Barrel Length: 

The length of your barrel affects muzzle velocity. Most muzzle velocities are measured between 24” and 26”, so if you want a shorter barrel, the muzzle velocity produced by each cartridge will be reduced accordingly within our comparator’s calculations.

Advanced Inputs (each has a default setting):

Muzzle Brake Recoil Reduction: 

The percent of recoil negated by the use of a muzzle device. Most modern muzzle brakes advertise about 20%-40%, and vary device to device. The default is 0% recoil reduction.

Maximum Shootable Recoil: 

Less recoil is always better than more recoil. You can set a maximum you are able to accurately shoot with, or set what you have shot before. The typical threshold is around a 10 pound rifle chambered in 30-06 Springfield at +/- 22 ft*lbs of recoil with no muzzle brake, but why have more than you need? The default is 25 ft*lbs.

Minimum Bullet Sectional Density: 

Sectional density (SD) is mathematically linked to bullet weight and ballistic coefficient (BC), and can be associated with higher penetration. This input is mostly for sorting out low performance bullets. Default is a sectional density of 0.21.

Minimum Bullet Impact Velocity: 

This is directly for proper bullet expansion. Most hunting bullets expand reliably above 1800 ft/s. Some users may desire to increase this to 2000 ft/s for a bit of wiggle room. The default is 1800 ft/s.

Altitude and Temperature: 

The altitude above sea level and temperature that you expect to be hunting; these metrics affect trajectory and muzzle velocity (gunpowder temperature stability). The default is 6000 feet above sea level and 60°F.

Action length: 

The action length is an industry standard description of the length of cartridge that your bolt action rifle can utilize and it is inherent to your rifle, the rifle you would like to buy, or the rifle you would like us to build for you. For clarity, a long action cartridge will not be able to be cycled properly in a short action, nor will a short action cycle in a long action properly. The choices are Short, Long, or Any/All, short actions fit cartridges like 6.5 Creedmoor and 308 Winchester, long actions fit cartridges such as 7mm PRC and 300 Winchester Magnum. Selecting All/Any will allow the comparator to plot both short and long actions. There are cartridges that benefit from a Medium or XM action from various custom action manufacturers, but this is an edge case that we can further discuss if you are interested in us building a custom rifle for you. Default is set to Any/All.

Thank you for using our Long Range Hunting Cartridge Comparator. We hope you found it useful and informative, and had as much fun using it as we had making it.

Appendix: List of Bullets Used in Ballistic Calculations for each Compatible Cartridge