GunSizer© was developed to do one thing. Allow you, the consumer, to compare the relative size and size differences between various modern-day handguns. To use this tool, simply select a handgun from each list and they will be compared to each other. Use the "Swap Handgun Positions" button to move the front handgun to the back. If you do not see a particular handgun in the list, please contact us and we will add it to the selection.