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The Second Amendment

A well regulated Militia, being necessary to the security of a free State, the right of the people to keep and bear Arms, shall not be infringed.

Selecting a Representative Cartridge

As stated in our disclosure, all of our ranking information is approximated and is calculated based on specifications of both the particular firearm and the caliber of cartridge used. One issue and resulting limitation in our calculations is that for a given handgun caliber there is usually a range of commercial cartridge loads that the gun can typically fire, and our calculations rely on only a single representative cartridge load for each caliber. 

How we have been, and are currently dealing with this issue in our calculations is by creating a single representative set of caliber specifications based the average and mean values of the range of cartridge loads commercially available for each caliber.

Let's take the .25 Auto cartridge as an example. Researching the cartridge we determined that there were three grain weights commercially available; 35gr, 45gr, 50gr. The average of these three values is 43.3gr. Rounding to the nearest whole grain weight we selected 43gr as the representative bullet weight for the caliber. We performed similar averages for muzzle velocity and muzzle energy across a range of production cartridges for the caliber.

Ultimately the representative cartridge specifications derived were of a 43gr bullet with an average muzzle velocity of 807 ft/sec and an average muzzle energy of 66 ft-lbs. But, in reality a cartridge with these specifications doesn't actually exist.

While these derived numbers work OK when comparing different .25 Auto handguns, they may not be as accurate when comparing different caliber handguns. Additionally, these numbers may not closely represent the actual cartridge load that is most commonly used for that caliber. And that's the biggest issue. What we really need to do is pick a specific real commercial cartridge load that best represents each given caliber. 

To do this we we collected production data from a large number of commercial ammo manufacturers. Here's the list of manufacturers we researched:

Aguila www.aguilaammo.com
Armscor us.armscor.com
Big Bear Firepower www.bigbearammo.com
Black Hills www.black-hills.com
Blazer www.blazer-ammo.com
Buffalo Bore www.buffalobore.com
CCI www.cci-ammunition.com
Cor-Bon www.corbon.com
Federal Premium www.federalpremium.com
Fiocchi www.fiocchiusa.com
Grizzly www.grizzlycartridge.com
Hornady www.hornady.com
HSM www.thehuntingshack.com
MagTech www.magtechammunition.com
PMC www.pmcammo.com
Prvi Partizan www.ppu-usa.com
Remington www.remington.com
Sellier & Bellot www.sellierbellot.us
Speer www.speer-ammo.com
Underwood www.underwoodammo.com
Ventura www.venturamunitions.com
Winchester www.winchester.com

From this list of manufacturers we identified 842 commercial cartridges produced for the 55 different calibers in our handgun database. We first organized the cartridges by caliber and grain weight. Then we selected the grain weight in each caliber with the highest popularity (number of cartridges with the same bullet weight produced across all manufacturers). From that group we ordered the cartridges by muzzle velocity and then muzzle energy, selecting the greatest mode (number of) or otherwise average from all in that group, deriving one single cartridge specification from the result. The following table shows the new selection method graphically for the .25 Auto caliber:

In this example we selected 50gr, 760 ft/sec, 64 ft-lb as the representative specification of a .25 Auto cartridge. Unlike the averaging method we have been using, this process produces specifications for a real cartridge. And most likely, it's the most common cartridge used in that caliber.

We applied this selection method to all 55 calibers currently in our database. We also checked the manufacturer's specifications against actual SAAMI test data of similar cartridges for verification. The result below is the list of representative cartridge specifications to be used in ranking handguns in their respective caliber. Those highlighted in green are manufacturers' specifications that are also matched with SAAMI test data.

You can view in detail the 842 commercial cartridges and the new cartridge selection process HERE.

Comments (7) -


By RPSGunsmithing at 1/20/2019 10:22:19 AM

Great approach and very informative. I would also like to see the average barrel length included with the data as well.

By Canoeal at 1/20/2019 1:17:04 PM

My only thought on the matter pertain to >2/22 mag handguns. I personally would prefer the information pertain to SD handgun specific rounds. Rifle rounds do not perform  as well out of  the shorter barrels. That and pay attention to barrel legths in general, as the 2_ 4- 6 inch barrels vary greatly in velocity, and muzzle energy.

By Canoeal at 1/20/2019 1:21:52 PM

22 mag out of  a 4" barrel is more like 1350 fps, and 164 ME. Out odf a 2' barrel it seems to drop tho 1150 fps amd 110  Me ..Can't really use the 20 barrel ballistics.

By Canoeal at 1/20/2019 1:38:30 PM

It seems that you are using rifle velocities in all of the rimfire calibers. It give and unrealistic value to the ME and effectiveness of the rounds I have a list that has realistic test rounds for the 22 Mag from 2" & 4" barrels. You can put them into a chart, to get more realistic MEs. I could email it to you. The realistic MEs range from 100-170 flbs. Velocities  seem to range between 1000-1500 fps...

By pebbycree at 1/20/2019 7:22:35 PM

Agree with your updated methodology. How much of an impact will this have on power factor/recoil factor calculations versus the old process?

By Admin at 1/21/2019 7:10:00 PM

The cartridge selection process won't have as much of an impact as our upcoming changes in our muzzle velocity calculations for changes in barrel length. There will be another article coming out shortly that will discuss how we currently approximate muzzle velocity and how we plan to improve it.

By Admin at 1/21/2019 7:25:14 PM

Selected specifications (grain weight, muzzle velocity/energy) are from manufacturer tests and SAAMI tests using specific test barrel lengths {and barrel types) for the given calibers and cartridge loads. Cartridges originally designed for rifles are typically tested with 20 to 24 inch test barrels. Revolver rounds are tested with vented barrels from 7.5 to 10 inches long.  Pistol rounds are tested in non-vented barrels from 2 to 10 inches in length. Details on test barrels will be presented in an upcoming article on how approximations and adjustments are made for different handgun barrel lengths and types.

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