Shooters Box patented Case / Cartridge gauge with Tri Step Face Design for 357 Sig.
Designed to measure the minimum case length (lower step), maximum case length (middle step), and also show SAAMI specs for maximum allowed chamber headspace (difference between middle and upper step which is the face of the gauge). See pictures for more information.
Made from Stainless Steel and built to last a lifetime. Each gauge is manufactured to SAAMI chamber / headspace specifications. The gauge will measure the maximum cartridge length (full overall length), the minimum and maximum case length, the maximum case diameter, and the minimum and maximum headspace. A loaded cartridge should fit freely and easily into the gauge. A cartridge that does fit properly may not correspond to the proper chamber dimensions.
Please read the following instructions for use from Shooters Box:
To use, place a clean cartridge into the gauge and make sure that it completely seats by itself with no assistance to seat it.
The head of the brass should sit within the lower and middle step of the gauge. If the cartridge sits higher than the middle step then your brass might be too long. If the head of the brass sits below the lowest step then your brass may be too short or the bullet crimp is too much. It's easy to check by eye or finger tip feel or with the help of a straight edge or steel rule.
With the cartridge in the gauge, check the backside to make sure the tip (bullet end) is not protruding outside the back face of the gauge. If the tip of the bullet protrudes from the end of the gauge the entire cartridge is longer than the maximum allowed cartridge length. If the cartridge does not easily drop into the gauge without assistance there is most likely something wrong with the dimensions of your cartridge. Any ammunition shown in the pictures is for representation purposes and is not included with this purchase.
Shooters Box advises to never attempt to resize loaded cartridges.
In some instances your cartridge may sit flush with the lower step BUT the brass may be shorter than the SAAMI minimum specifications. In this instance your ammunition may still fire and function correctly but it is up to you to confirm this will not cause an unsafe condition. It is the reloader's responsibility to determine the cause of incorrectly sized cartridges and to correct it. In some cases ammunition previously fired with maximum powder loads or with abnormally large barrel chamber diameters may not fit this gauge. This is due to some resizing dies not being able to fully resize the brass cartridge all the way down to it's head. Any ammunition shown in pictures is purely for representation purposes and is not included with the purchase of this gauge.