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:
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.