Firearm Repair & Restoration Techniques Flashcards

When fitting a new extractor to a semi-automatic pistol, the gunsmith should verify correct tension by:

Answer: Pressing a loaded cartridge rim under the extractor and confirming snap-in with firm resistance

Proper extractor tension is confirmed when a cartridge snaps under the extractor with firm resistance and does not rattle or fall out when the pistol is tilted.

A double-action revolver's trigger pull is excessively heavy. Which spring is most often replaced or reduced to improve DA pull weight?

Answer: Mainspring (hammer spring)

The mainspring (hammer spring) is the primary contributor to double-action trigger pull weight, and replacing it with a reduced-power unit is the standard approach.

During a stock inlet repair on a wood-stocked rifle, the gunsmith finds a cracked wrist. The preferred structural repair method is to:

Answer: Inject thin cyanoacrylate into the crack, clamp, and reinforce with a hidden steel cross-pin if needed

Thin CA wicks into the grain, bonds the crack, and a cross-pin provides mechanical reinforcement in high-stress wrist areas.

What does a 'go' gauge confirm when checking chamber dimensions?

Answer: The bolt will close on a cartridge at minimum safe headspace

A go gauge is machined to minimum headspace; if the bolt closes on it, the chamber is at least at minimum safe dimensions and will accept factory ammunition.

A shotgun with a loose action body-to-stock joint is being repaired. After tightening the stock bolt, the correct next step is to:

Answer: Bed the action in the stock using an epoxy bedding compound

Epoxy bedding fills micro-gaps and creates a perfect, stress-free mating surface between the action and stock, eliminating the play that causes looseness.

When polishing the feed ramp of a 1911-style pistol, the gunsmith should avoid removing material from which area?

Answer: The junction of the frame ramp and the barrel ramp (the ramp-to-ramp transition)

Removing material at the ramp-to-ramp transition creates a gap or ledge that catches cartridge noses, causing the very feed failures the polish was meant to prevent.

Which method is used to identify high spots when fitting a bolt's locking lugs for full-contact engagement?

Answer: Coat the lugs with machinist's blue (Dykem) and close the bolt to reveal contact marks

Machinist's blue (Dykem) transfers off the lugs onto the receiver seats where contact occurs, clearly showing which areas are bearing and which need lapping.