Find Barrel Thickness & Concentricity Before You Try To Thread
Know exactly whether a customer’s barrel has adequate wall thickness before accepting and machining it for screw-in chokes. Unique design allows the gunsmith to mount the instrument (not the barrel) in a bench-top vise for ease of use and fast, accurate measurements. Aluminum block with steel probe and gauge arm provide excellent stability and consistency. High-grade, Procheck brand, dial indicator measures to .001". Helps check barrel concentricity, too.
Big Book Catalog, Issue:69, Page:478
SPECS: Aluminum and steel, natural finish. 18¾"
(47.6cm) long x 5" (12.7cm) high.