Thanks Jack, I don’t remember seeing a second row of images in the Kindle version of the book that I purchased recently. I have been researching further trying to understand more about the action of the Carcano rifle. Below please find a Q&A that I think might be pertinent.
For what it is worth:
Question to Google AI:
if the bolt handle of a Carcano model 91-38 rifle is slightly not completely down in the closed position can the trigger still be pulled and the rifle fire and if so, can this cause a variation in the depth of the firing pin depression in the primer of the cartridge?
Google AI answer:
Yes, a Carcano Model 91/38 can be fired with the bolt handle slightly unlatched. Because of the design of the cocking cams, pulling the trigger releases the firing pin even if the bolt is not fully locked down.
The Mechanics:
Trigger Pull and Firing: Most bolt-action rifles are designed with an "out of battery" safety that disconnects the sear or physically blocks the firing pin if the bolt is not fully closed. However, the historic Carcano M91 design lacks this modern feature. When the bolt handle is slightly raised:The trigger can still be pulled, releasing the cocking piece and firing pin. As the firing pin drives forward, its energy is often spent camming the bolt handle downward into the locked position before the pin hits the primer. Alternatively, if the bolt is held firmly in place so it cannot self-close, the firing pin will release and strike the primer while the bolt remains partially out of battery.
Effect on Firing Pin Depth (Primer Indentation):
If the bolt fails to fully lock down, it fundamentally alters the headspacing of the firearm. When the trigger is pulled:Inconsistent Depth: You will likely notice a variation in the depth of the firing pin depression. If the firing pin's forward energy is robbed by the effort of forcing the bolt to cam into battery, the indent will often be shallow, light, or off-center.
Safety Risks: Firing a rifle "out of battery" (when the bolt lugs are not fully seated and locked into the receiver) is extremely dangerous. It exposes the unsupported or partially supported cartridge case to high pressures, which can cause ruptured brass, blown primers, and escaping gas that could damage the firearm or injure the shooter.
For more context on how these components function, you can view the Carcano Bolt Disassembly and Reassembly guide.
I guess it depends on which AI is being used. This is COPILOT.
JN “can a M38 carcano rifle be discharged without the bolt fully closed”
Short answer: No. An M38 Carcano cannot discharge unless the bolt is fully closed and locked. This is a hard mechanical rule of the Carcano action — not something that varies by model.
🔧 Why the M38 cannot fire out of battery
The M38 uses the same fundamental Carcano turn‑bolt system as the M91/38 and earlier long rifles. Three mechanical interlocks prevent firing unless the bolt is fully rotated down:
1. Front locking lugs
The firing pin cannot reach the primer unless the bolt lugs are fully engaged in their recesses. If the bolt is even slightly up, the lugs block firing‑pin travel.
2. Firing‑pin cam block
The cam track on the bolt body physically stops the firing pin from moving forward until the bolt handle is fully down. This is a positive mechanical stop, not a soft interference.
3. Cocking piece/sear alignment
The sear only releases the cocking piece when the bolt is in the locked position. If the bolt is not fully closed, the trigger may “click,” but the firing pin cannot travel.
🧪 What happens if you try to fire with the bolt slightly open
On a Carcano (including the M38):
The trigger can release the cocking piece.
The firing pin begins to move forward.
The cam block stops it before it reaches the primer.
Result: a dry click, no ignition.
There is no known case — in military testing, civilian use, or forensic examination — of a Carcano firing out of battery.
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It looks like the difference is really does the firing pin release even though you are hearing the click. One AI says it does the other says it does not. The ones I messed with I could not tell. I did notice when the bolt is rotated and the spring is engaged the bolt can no longer move and is tight to the chamber.