Firearms Examination Unit Technical Procedures

Open the jaws of the caliper and measure the widths of the 0.500 inch and 1.000 inch gage blocks. Use the entire surface of the jaws, being careful to hold the caliper level. The acceptable ranges for these measurements must be 0.500 +/- 0.001 inches and 1.000 +/- 0.001 inches, respectively. ................
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