NRA Tools & Equipment for Gunsmithing Flashcards

What is a 'torque wrench' used for in gunsmithing, and give one common application?

Answer: Applying a specific, measurable amount of rotational force — commonly used for tightening scope base screws to manufacturer specification

A torque wrench ensures fasteners are tightened to the correct specification — critical for scope bases, action screws, and muzzle devices to prevent under- or over-torquing.

What is a 'stock inletting tool' (or inletting scraper) used for?

Answer: Removing wood from the interior of a stock to achieve a precise, tight fit between the action and stock

Inletting scrapers precisely remove small amounts of wood from a stock's interior to achieve a glass-smooth, tight bedding fit between the action and wood.

What is a 'feeler gauge' used for in firearm diagnostics?

Answer: Measuring small gaps and clearances, such as cylinder gap on a revolver or frame-to-slide clearance

Feeler gauges are thin metal blades of precise thickness used to measure small gaps — for example, the cylinder-to-barrel gap on a revolver.

What is a 'scope level' and why does a gunsmith need one during scope installation?

Answer: A leveling device used to ensure the scope's reticle is perfectly level relative to the bore, preventing cant-induced point-of-impact errors

A canted reticle causes point-of-impact to shift left or right at distance, so using a scope level during mounting ensures the crosshair is perfectly plumb with the bore.

What is 'inletting black' used for in stock work?

Answer: A transfer compound applied to metal parts to identify where the metal contacts (and needs material removed from) the wood inlet

Inletting black transfers from metal to wood, showing exact contact points so the gunsmith can precisely remove material for a perfect, tight bedding fit.

What is a 'chamber cast' (Cerrosafe casting) and when would a gunsmith perform one?

Answer: A low-melting-point metal alloy poured into the chamber to create an exact three-dimensional cast for measuring chamber dimensions

A Cerrosafe chamber cast provides a precise replica of the chamber that can be measured with calipers to determine actual chamber dimensions, useful for identifying unknown calibers or diagnosing headspace issues.