NRA Metalworking & Woodworking for Gunsmithing 2

Question 1

Which drill bit geometry is best suited for drilling into hardened steel during gunsmithing repairs?

Accepted Answer

Carbide-tipped or cobalt drill bit

Answer

Carbide-tipped or cobalt drill bits maintain cutting edges at the high temperatures generated when drilling hardened steel.

Question 2

When silver soldering a front sight to a barrel, what is the correct flux application sequence?

Accepted Answer

Apply flux to cold, clean metal before heating

Answer

Flux must be applied to clean, cold metal before heating to prevent oxidation and ensure proper solder flow.

Question 3

What is the primary purpose of draw filing a metal surface?

Accepted Answer

Producing a fine, smooth finish by dragging the file sideways

Answer

Draw filing involves pushing or pulling a file laterally across the work to refine and smooth a surface after regular filing.

Question 4

A gunsmith needs to tap a hole for a 10-32 scope base screw. What drill size should be used for the tap drill?

Accepted Answer

No. 21 (0.159")

Answer

A No. 21 drill (0.159") provides approximately 75% thread engagement, which is standard practice for 10-32 threads in firearm applications.

Question 5

Which wood grain orientation provides the greatest impact resistance for a rifle stock?

Accepted Answer

Straight vertical grain running the length of the stock

Answer

Straight vertical grain (quarter-sawn) running lengthwise is strongest because wood fibers align with the primary stress direction during recoil.

(NRA) National Rifle Association Certified Gunsmith Practice Test