Metalworking & Woodworking for Gunsmithing Flashcards

Which type of steel is most commonly used for rifle barrels due to its combination of strength and machinability?

Answer: 4140 chromoly steel

4140 chromoly steel offers an excellent balance of tensile strength, toughness, and machinability that makes it the industry standard for rifle barrels.

When fitting a new wood stock blank to a metal action, what is the correct sequence of inletting?

Answer: Inlet the action first, then work outward to the barrel channel

Starting with the action inletting establishes the critical fit at the receiver, then extending the barrel channel ensures proper alignment throughout.

A gunsmith is using a mill to cut a dovetail slot for a front sight. What cutter geometry is required?

Answer: Dovetail cutter with angled sides

A dovetail cutter has angled cutting faces that produce the characteristic trapezoidal profile needed to capture a dovetail-base sight.

What does the Rockwell hardness scale 'C' (HRC) primarily measure in gunsmithing contexts?

Answer: Surface hardness after heat treatment

The Rockwell C scale uses a diamond cone indenter under load to measure surface hardness, commonly used to verify heat treatment results on hardened firearm parts.

When checkering a pistol grip using a 60-line-per-inch pattern, what is the primary purpose of the master lines cut first?

Answer: To establish the pattern layout and spacing guides for subsequent cuts

Master lines establish the grid spacing and direction so all subsequent cuts remain parallel and evenly spaced throughout the checkering field.

Which heat treatment process is used to relieve internal stresses in a steel part after machining without significantly changing its hardness?

Answer: Stress relieving

Stress relieving heats the part below the critical transformation temperature and slow-cools it, eliminating machining stresses without major changes to hardness or microstructure.

What finish is applied to wood stocks to raise the grain before final sanding to achieve a glass-smooth result?

Answer: A water or solvent wash to raise grain fibers before sanding

Wiping the sanded stock with water or a grain-raising solvent causes wood fibers to swell and stand up, which are then sanded off to produce a smoother final surface.