Measure pellet head diameters to 0.01 mm accuracy
PelletGage is a simple to use device to determine the head size of pellets in 0.01 mm (ten micron) increments. Orders are now being accepted for immediate shipment.
There are five ranges has ten round apertures precisely cut into a thin metal sheet. Accuracy of the diameters is assured by a state of the art laser cutting special alloy sheet steel - tolerance is +/- 0.0025 mm of indicated inside diameter. These range as follows:

cal     range
.177   4.46 to 4.55 mm
.20     5.02 ro 5.11
.22     5.48 to 5.57
.25     6.33 to 6.42
.30     7.58 to 7.67

To use it, roll or drop the head of the pellet into the smallest expected aperture. If the pellet head is larger, it will not drop into the opening. Move up to the next larger size(s) - diameters are etched in the metal - and the pellet will drop partially through aperture, caught by the skirt. This establishes the size range of the pellet head as being between the largest aperture it won't clear, and the smallest that it will (commonly called a go/no-go).

The gage openings are cut through 0.008" type 304 SS sheet metal by a diode pumped fiber optic laser. PelletGage can be used to rapidly sort pellets by size, or simply to give you an accurate measure of the head diameter of that new tin of pellets you just received. Once you know what diameter your gun "likes", you can take steps to get that same diameter for better shooting results. You’ll be confident in that variable of the quest for accuracy.

Testing has shown significant size variation in tins of quality pellets, and differences of mean diameter between tins of the same size and weight. This may be a key to finding that next tin of pellets that shoots so well. It can also be used to check the diameter of pellets used to "slug" a barrel.

PelletGage is more accurate, repeatable, and faster than using calipers or micrometers - and doesn't demand the concentration of those devices.

The steel used is the tough alloy 304 - hot rolled sheet that has been cold rolled and annealed. It is durable, but should be used with care. Don't force anything through the opening, especially a hard material. Used with care, your gage will last for many years of checking lead pellets.