Since starting the HAM pellet test reviews, we’ve received several messages asking how we test pellet head diameters. In fact, we use a tool called the Pelletgage – and now there’s a BBGage as well!
There was a full description of the Pelletgage in HAM in a previous issue. So we won’t cover it again here. But we can say that we find it easy and precise to use as a tool to measure pellet diameters.
And so that we can measure BB diameters, we’ve just received a BBGage. It’s the one on the right in our heading photo above.
Because BBs are smaller in diameter than .177 caliber pellets, the BBGage has a different set of “go no go” apertures. In fact, they range from 4.35 mm up to 4.44 mm, in increments of 0.01 mm (that’s just under 4 Thou, if you’re working in inches). This range compares to sizes between 4.46 mm and 4.55 mm for the .177 PelletGage.
In fact, each aperture in the BBGage is calibrated to +/- 0.0025 mm (0.0001 inch, or 1/10th of a Thou). That’s precision!
The BBGage itself is made from specially treated 304 stainless steel sheet, hot rolled, then cold rolled, then annealed. It should last indefinitely with careful use.
Usage is very simple. The BB is measured to be the size of the smallest aperture that it will pass through. The BBGage will also reject oval BBs, or ones that are otherwise defective in shape.
HAM will be running some BB test reviews in future. And when we do, the BBs will have their diameter measured using the BBGage.
The PelletGage is available in all popular airgun calibers, including .177 cal, .20 cal, .22 cal, .25 cal and .30 caliber. They are available directly from the inventor/manufacturer at www.pelletgage.com
Below, PelletGages in .177 and .25 calibers.