NRA NRA Firearm Inspection & Testing Procedures 2 — Questions and Answers
Question 1: What is 'trigger overtravel' and how does a gunsmith check for it?
- The distance the trigger travels before the sear releases — checked with a ruler
- The movement of the trigger after the sear releases the hammer or striker — checked by feel and measured with gauges or observation (Correct answer)
- The distance from the trigger face to the back of the trigger guard
- The total trigger weight divided by the spring tension
Correct answer: The movement of the trigger after the sear releases the hammer or striker — checked by feel and measured with gauges or observation
Overtravel is trigger movement after the sear breaks — excessive overtravel can disrupt aim; gunsmiths check it by feel and can measure it with a dial gauge.
Question 2: What does inspecting the 'forcing cone' of a revolver barrel involve, and why is it important?
- Checking the cylinder gap with a feeler gauge
- Examining the tapered entry of the barrel for cracks, erosion, or out-of-spec dimensions that affect bullet transition from cylinder to bore (Correct answer)
- Measuring the overall barrel length for legal compliance
- Checking whether the barrel is properly threaded to the frame
Correct answer: Examining the tapered entry of the barrel for cracks, erosion, or out-of-spec dimensions that affect bullet transition from cylinder to bore
The forcing cone guides bullets from the cylinder into the bore, and cracks, erosion, or incorrect angles cause leading, pressure loss, and accuracy problems.
Question 3: What is 'trigger creep' and how does it differ from overtravel?
- Creep is movement after the sear breaks; overtravel is movement before
- Creep is undefined travel and takeup before the sear breaks; overtravel is movement after the sear releases (Correct answer)
- They are the same thing described differently by different manufacturers
- Creep refers to trigger return speed; overtravel refers to trigger forward movement
Correct answer: Creep is undefined travel and takeup before the sear breaks; overtravel is movement after the sear releases
Trigger creep is the mushy, undefined movement before the sear breaks, while overtravel is the movement after — both can negatively affect accuracy.
Question 4: What does a gunsmith look for when inspecting a semi-automatic pistol's feed ramp?
- Scratches from cleaning brushes — these are acceptable
- Wear patterns, gouges, burrs, or incorrect angles that could impede reliable cartridge feeding (Correct answer)
- The feed ramp's color to identify metal type
- Whether the feed ramp is polished to a mirror finish — required for function
Correct answer: Wear patterns, gouges, burrs, or incorrect angles that could impede reliable cartridge feeding
Feed ramp defects — burrs, incorrect angles, or rough surfaces — cause feeding failures, and identifying the pattern of wear helps diagnose reliability issues.
Question 5: When performing a safety inspection on a used bolt-action rifle, what should be checked regarding the trigger sear engagement?
- Whether the trigger pull is under 1 pound
- That the sear has adequate engagement depth to prevent accidental firing, especially when the safety is disengaged or the bolt is closed forcefully (Correct answer)
- Whether the trigger shoe is the correct width
- That the sear is made of stainless steel
Correct answer: That the sear has adequate engagement depth to prevent accidental firing, especially when the safety is disengaged or the bolt is closed forcefully
Insufficient sear engagement can allow the rifle to fire without a trigger pull, especially after rough handling — a critical safety concern requiring adjustment or repair.
Question 6: What is a 'borescope' and why is it valuable in gunsmithing?
- A device that measures bore diameter at multiple points
- A small camera or optical instrument inserted into the bore for detailed visual inspection of the rifling, throat, and crown (Correct answer)
- A tool that measures chamber concentricity
- A pressure-testing instrument inserted through the bore
Correct answer: A small camera or optical instrument inserted into the bore for detailed visual inspection of the rifling, throat, and crown
A borescope allows the gunsmith to visually inspect the full length of the bore for erosion, pitting, fouling, cracks, or obstructions without disassembly.
NRA NRA Firearm Inspection & Testing Procedures 2
What is 'trigger overtravel' and how does a gunsmith check for it?