NRA Firearm Customization & Modifications 5

Question 1

A customer wants to convert their Ruger 10/22 to a bull barrel configuration. What must the gunsmith verify before recommending an aftermarket bull barrel?

Accepted Answer

That the stock's barrel channel is wide enough to accept the larger diameter, or that a new stock is used

Answer

A bull barrel has a larger outside diameter than the factory barrel; the stock's barrel channel must be opened up or replaced to accommodate the larger profile and achieve proper or free-float fit.

Question 2

When installing an extended magazine release on a Glock pistol, what tool is required to remove the factory magazine catch?

Accepted Answer

A 3/32-inch punch to depress the locking block pin and a 1/8-inch punch to drive the magazine catch pin

Answer

Glock magazine catch removal requires depressing the locking block pin with one punch while driving the magazine catch pin out with another, a two-punch process unique to Glock disassembly.

Question 3

A rifle's groups are shifting point of impact after the barrel heats up. What bedding or barrel modification would most likely resolve this?

Accepted Answer

True free-floating the barrel so the stock exerts no upward pressure on the barrel at any temperature

Answer

Heat causes wood and some synthetic stocks to expand and change pressure points on the barrel; true free-floating eliminates all contact between barrel and stock, removing this variable.

Question 4

What is the primary reason a gunsmith would use a chamber reamer stop collar when chambering a barrel?

Accepted Answer

To control how deep the reamer cuts, preventing over-chambering and tight headspace

Answer

A stop collar limits the reamer's cutting depth, allowing the gunsmith to creep up on the correct headspace incrementally without accidentally cutting the chamber too deep.

Question 5

When installing an aftermarket extended slide stop lever on a 1911 pistol, what function must be verified after installation?

Accepted Answer

That the lever does not engage (lock the slide open) inadvertently during firing due to shooter contact

Answer

Extended slide stop levers can be inadvertently pressed by the shooter's thumb during firing, causing the slide to lock back mid-magazine; function testing with live-fire is essential.

(NRA) National Rifle Association Certified Gunsmith Practice Test

(NRA) National Rifle Association Certified Gunsmith Practice Test

NRA Firearm Customization & Modifications 5