Last Gun Alchemist-Chapter 75: Preparations for the Next Trial Part Two

Joint Alchemy, from the name alone, the concept sounded simple.

It is the cooperation of several alchemists, combining their Cognis together in order to perform alchemy that normally required a higher rank, but the process itself was not simple at all.

Alchemy had changed many times since the discovery of Cognis and the rise of Britannia.

In the earliest era, alchemy required preparation that felt almost ritualistic. Multiple alchemists would first draw a complete alchemy circle on a clean surface—sometimes on the ground, sometimes on large scrolls made for that purpose.

The circle had to be precise.

Every line, every symbol.

Even the smallest mistake could cause the alchemy to fail or collapse midway. Since it was been drawn by hand, human error was a big factor that could cause the alchemy to fail.

Once the circle was complete, the materials needed for the transformation were placed carefully inside the formation.

Then the alchemists would activate the process.

This was the oldest method, but time moved forward.

As the understanding of Cognis improved, alchemists learned to control their Cognis more directly. The era of drawing circles on the ground slowly faded.

Instead, many alchemists learned to form the alchemy circle in the air between their palms.

A simple clap of the hands would ignite the process to create the circle.

Then they would bring their palms down onto the materials and activate the transformation.

It was faster.

More efficient.

But the old method never disappeared.

Because when several low-rank alchemists worked together, drawing a large circle beforehand still allowed them to combine their Cognis more effectively.

That was where Joint Alchemy showed its greatest strength.

By sharing their Cognis and preparing the circle in advance, weaker alchemists could execute transformations that normally belonged to higher ranks.

***

Ezra walked into the library later that afternoon.

The place felt unusually quiet.

Normally the library held scattered students reading books or whispering about theories, but today most of the tables were empty.

Everyone was busy preparing for the fifth trial.

Weapons, materials, defensive plans.

The tower defense trial had pushed every faction into action.

Ezra, however, had come here for a different reason.

He was not here to read books.

He was here to organize his thoughts.

He walked toward his usual table and sat down.

The wooden chair creaked slightly under his weight.

Ezra leaned forward, resting his elbows on the table, then he placed his chin on both hands.

His eyes stared at the empty chairs across from him.

The library windows allowed pale daylight to fall across the long tables. Dust floated slowly through the beams of light, drifting lazily in the quiet air.

When he saw the design of the tower earlier, an idea had appeared in his mind.

Not just any weapon.

A perfect weapon for this trial.

A weapon that could kill in one shot from a very long distance.

But there was another reason he had insisted on handling one side of the tower almost alone.

Secrecy.

Ezra understood alchemists.

Curiosity was part of their nature.

If he created a weapon they had never seen before, they would ask questions.

Too many questions.

What kind of gun was it? How was it made? What kind of alchemy produced it?

And once their curiosity began, they would not stop.

Ezra let out a slow breath.

"At the end of the day..."

His voice was quiet.

"That was still the best option."

He stared at the empty chairs again.

Speaking to himself felt strange, but the quiet library made it easy.

"I also wouldn’t want to listen to them nag all the time."

He exhaled slowly.

Then Ezra opened the Book of Memories inside his mind.

A familiar page appeared, information began to unfold before his eyes.

The name of the weapon appeared clearly.

***

Barrett M82 / Barrett M107

A large-caliber semi-automatic rifle engineered for long-range destructive capability. Unlike conventional rifles designed primarily for infantry combat, this platform was created for anti-materiel operations, meaning it is intended to damage equipment, vehicles, radar installations, and fortified structures.

The rifle fires the .50 Browning Machine Gun cartridge (.50 BMG / 12.7×99 mm)—one of the most powerful cartridges used in shoulder-fired firearms.

Operational Principle

The weapon functions through a short-recoil semi-automatic system.

Upon firing, expanding gases propel the projectile through the barrel while simultaneously forcing the barrel and bolt assembly to move rearward together for a short distance. This synchronized movement absorbs a portion of the immense recoil energy produced by the .50 BMG cartridge.

After this short rearward travel:

The bolt unlocks

• The spent casing is extracted and ejected

• A recoil spring drives the bolt forward again

• A fresh cartridge is stripped from the magazine and chambered

This cycle allows the rifle to fire repeatedly without manual bolt operation.

Structural Composition

The rifle is constructed to survive extreme mechanical stress. Its components are significantly heavier than those of ordinary rifles due to the high pressures generated during firing.

Barrel

The barrel is manufactured from high-strength chrome-moly steel alloys designed to endure chamber pressures exceeding 50,000 pounds per square inch (psi). The barrel walls are thick in order to resist deformation caused by internal pressure.

A large multi-baffle muzzle brake is mounted at the front of the barrel. Its purpose is to redirect high-velocity propellant gases sideways and backward, reducing felt recoil by as much as 60–70%.

Without this system, the recoil force would be extremely difficult for a human operator to control.

Receiver and Frame

The receiver acts as the structural backbone of the rifle. It houses the bolt assembly, recoil springs, and feeding system. This section is typically machined from aircraft-grade steel or high-strength alloy metals to prevent fatigue or cracking during repeated firing cycles.

The rifle’s overall mass is deliberately high—often exceeding 13 kilograms when fully equipped. This weight is not accidental; it acts as a mechanical buffer that absorbs recoil momentum.

Bolt and Locking System

The bolt uses multiple locking lugs that rotate into engagement with the barrel extension. When locked, these lugs distribute chamber pressure evenly across the bolt face and receiver structure.

This locking system ensures that the bolt remains sealed while the cartridge is under peak pressure.

Only after the projectile exits the barrel and pressure drops does the bolt unlock and cycle rearward.

Magazine System

The rifle feeds from a detachable steel box magazine.

Magazine Type: Detachable box magazine

Capacity: 10 rounds

Because the .50 BMG cartridge is extremely large—approximately 5.45 inches (138 mm) long—magazine capacity must remain relatively small.

The magazine is inserted from the underside of the receiver and feeds cartridges upward into the bolt path.

Ballistic Characteristics

The .50 BMG projectile typically weighs between 647 and 750 grains and exits the barrel at velocities around 850–900 meters per second depending on ammunition type.

This generates enormous kinetic energy.

The energy of the projectile can be approximated using the kinetic energy equation:

[

E = \frac{1}{2}mv^2

]

Where:

(m) = projectile mass

• (v) = muzzle velocity

Because velocity is squared in the equation, even small increases in speed produce massive increases in impact energy.

This is why the rifle can disable light vehicles, penetrate hardened materials, or destroy mechanical equipment at long distances.

Engineering Considerations

Several physical principles govern the rifle’s design.

Chamber Pressure Resistance

The barrel and bolt must withstand extreme internal pressures created by burning propellant. Engineers calculate allowable stress using cylindrical pressure equations such as:

[

\sigma = \frac{P r}{t}

]

Where:

(σ) = stress on barrel walls

• (P) = internal pressure

• (r) = bore radius

• (t) = wall thickness

This determines the minimum thickness required for the barrel to remain structurally stable.

Recoil Momentum

The recoil generated by the rifle is a result of conservation of momentum.

[

m_{bullet} \times v_{bullet} = m_{rifle} \times v_{recoil}

]

To keep recoil manageable:

The rifle mass is increased

• A muzzle brake redirects gas momentum

• Recoil springs absorb kinetic energy

These elements work together to prevent the weapon from becoming uncontrollable.

Performance Characteristics

Caliber: .50 BMG (12.7×99 mm)

• Operation: Short-recoil semi-automatic

• Magazine Capacity: 10 rounds

• Barrel Length: Approximately 29 inches

• Effective Range: Up to 1,800 meters depending on optics and ammunition

• Weapon Mass: Roughly 13–14 kilograms

Analytical Summary

The Barrett M82/M107 represents a firearm designed at the upper limits of shoulder-fired ballistic engineering. Its massive caliber, recoil management systems, and reinforced structure allow it to fire ammunition normally associated with heavy machine guns while still remaining portable enough to be operated by a single individual.

In practical terms, it is less a conventional rifle and more a mobile precision weapon capable of delivering anti-materiel firepower across extreme distances.

***

Ezra stared at the lines of information describing the sniper rifle.

The words seemed clear, almost too organized, as if someone had carefully arranged them for study.

"So... it’s a sniper," he muttered under his breath, eyes moving slowly across the page, reading every line without skipping a single word. "But it’s not exactly classified as one."

He kept reading.

His eyes narrowed slightly.

"Hmmm..."

The small reaction escaped him before he even realized it.

Ezra’s eyes twitched faintly.

"The way the book shows the information... it seems different."

He leaned closer to the table.

His gaze moved from one section to another.

The highlighted titles, the analytical summary, the performance characteristics, the recoil momentum explanation.

Each section was arranged neatly, like a technical report rather than simple notes.

Ezra slowly tapped the table with one finger as he read again.

"It feels like a full layout of the Barrett M82 and M107..."

He paused.

The thought lingered in his mind, for a moment he did not move.

His eyes shifted slightly to the left as his posture on the chair changed. He leaned back a little, letting his shoulders rest against the wooden backrest.

Like the past me, wrote all of this...

The idea surfaced quietly in his mind.

Is it because of the unlocked memories?

His gaze lowered slightly.

Then...

The image came.

Flashes of blood, the broken room, the sound of screams that never finished.

The scene of the family he slaughtered appeared for less than a second before disappearing just as quickly.

Ezra blinked once.

Then he exhaled slowly.

"This is better," he muttered.

His fingers tapped lightly on the table again as his focus returned to the information before him.

"At least with the way the layout is now... I can work faster."

His eyes sharpened slightly.

"I should be able to finish converting the alchemy circle by the second day."

He spoke quietly, calculating in his head.

"All I need now are the right materials."

He rubbed the side of his temple briefly.

"If I can gather the proper components, it will reduce the percentage of Cognis needed for the transformation."

Ezra leaned back fully in his chair.

The wooden legs creaked faintly against the library floor.

His eyes remained on the page floating in his mind.

"Normal sniper rifles usually rank at Adept level or above because of their long range and destructive power."

He spoke slowly, almost like he was explaining the thought to himself.

"But this one..."

His gaze focused again on the weapon’s structure.

"If it’s constructed properly, this rifle will easily reach Arcanist rank."

He paused briefly.

"Of course..."

"I’ll have to work with the materials available here."

Even if the alchemy result came out weaker than expected, he had already considered the outcome.

"Even if it ends up as a Second-Grade weapon, it will still be strong enough to use the rifle’s full rounds."

Ezra nodded slightly to himself.

The thought did not bother him, power could always be improved later. What mattered right now was functionality.

"Before the trial begins..."

His fingers tapped the table again.

"I should also prepare twenty to fifty magazines."

His voice dropped slightly.

"Ten shots for each monster head."

The calculation was simple.

A monster wave meant numbers and numbers required preparation.

Ezra continued thinking quietly, his lips moving slightly as he organized the plan in his mind.

Then he suddenly stopped.

"Oh."

He raised his head slightly.

"Before I forget..."

"I should also check out the best scope for the Barrett rifle."

The moment the thought formed...

The page inside his mind moved.

As if responding to his intention, the information on the rifle shifted.

The page flipped.

A new section appeared immediately.

Detailed diagrams and notes began to show the optical systems compatible with the rifle, along with several recommended scopes.

Ezra’s eyes sharpened again as he leaned forward slightly on the table.

***

[Optical System Analysis]

Compatible Weapon Platform: Barrett M82 / Barrett M107

The rifle does not rely on a fixed optical sight. Instead, it uses a Picatinny rail mounting interface, allowing a wide range of detachable optical scopes to be installed depending on operational requirements.

This modular rail system enables the rifle to mount precision optics capable of functioning under the extreme recoil forces generated by the .50 BMG (12.7×99 mm) cartridge.

Recommended Optical System

Primary Choice: Nightforce NXS 5.5‑22×56

This scope is widely considered one of the most effective optics for large-caliber precision rifles.

Key characteristics include:

Variable magnification range of 5.5× to 22×

• Large 56 mm objective lens for increased light collection

• Reinforced internal construction designed to withstand high recoil forces

• Precision adjustment turrets for elevation and windage corrections

The scope’s magnification range allows targets located over one kilometer away to be observed and engaged with improved clarity.

Alternative Military-Grade Optic

Leupold Mark 4 LR/T

This optic is commonly used in military sniper systems due to its durability and consistent optical clarity.

Features include:

Tactical mil-dot reticle for distance estimation

• Precision turret adjustments

• High resistance to mechanical shock and vibration

Optical Mechanics

Long-range rifle scopes function by magnifying distant targets through a system of lenses arranged within the scope body.

Key components include:

Objective Lens – gathers incoming light from distant objects

• Erector Assembly – adjusts magnification levels

• Reticle – reference markings used for aiming and distance estimation

• Ocular Lens – presents the magnified image to the shooter’s eye

The internal lenses bend and focus incoming light to create a clear and enlarged image of distant objects.

Magnification Range

Typical optics used with this rifle fall within the range of:

4.5× – 14×

• 5.5× – 22×

• 5× – 25×

Higher magnification allows the shooter to observe targets at extreme distances while adjusting aim for environmental factors.

Reticle System

Most long-range optics utilize Mil-Dot reticles.

The reticle consists of evenly spaced dots or hash marks that allow estimation of target distance.

Distance estimation follows the relationship:

[

Distance = \frac{Target\ Size}{Mil\ Measurement} \times 1000

]

Where:

Target Size = estimated height or width of the object

• Mil Measurement = number of reticle mils covering the target

This calculation helps determine bullet drop compensation.

Operational Role

The optical system transforms the rifle from a simple ballistic weapon into a long-range precision platform.

By magnifying distant targets and providing mathematical reference points for trajectory adjustment, the scope allows accurate engagement of objects at distances approaching 1,800 meters.

Analytical Conclusion

Because the Barrett platform generates extremely high recoil forces, only heavily reinforced tactical scopes are suitable for long-term operation. Optics such as the Nightforce NXS and Leupold Mark 4 are specifically engineered to maintain optical alignment and mechanical precision even after repeated exposure to large-caliber recoil.

***

A thin line of cold sweat rolled down Ezra’s temple, but it wasn’t fear.

It was exciting.

The information before him was clear and precise. Every section explained the weapon in a way that was easy to follow. For someone like Ezra, whose mind could break things apart and rebuild them quickly, the layout felt almost perfect.

His lips slowly curved upward.

Ezra smirked.

Without wasting another second, he reached into his bag and pulled out a rough jotter along with several loose sheets of paper. The pages were already filled with sketches and symbols, some messy, some carefully drawn.

He flipped to one particular page.

At the center of it was an incomplete alchemy circle.

Inside the circle was the rough structure of the Barrett rifle he had started designing before the fourth trial commenced.

Ezra placed the jotter flat on the table and leaned forward.

The wooden chair scraped slightly as he adjusted his position. His elbow rested on the table while his other hand held the pen tightly.

"Alright..."

He muttered quietly to himself.

His eyes moved back to the information floating in his mind.

Then back to the page.

He began working.

Line by line, he broke the information apart.

The barrel structure, short-recoil system, bolt mechanics, magazine feed.

Each section was translated slowly into alchemical form.

Ezra drew additional circles branching out from the main formation. Inside them he began inserting alchemy symbols that represented pressure, motion, energy transfer, and structural reinforcement.

The sound of the pen scratching across the paper became the only sound around him.

The quiet library made it easier to focus.

Occasionally Ezra paused.

Not because he was confused, but because he was rearranging the structure inside his head before committing it to paper.

He would stare at the circle for a few seconds, then add another line.

Or erase a symbol and redraw it somewhere else.

The Barrett’s recoil system required special attention.

If the alchemy circle failed to replicate the recoil absorption correctly, the weapon might destroy itself after the first shot.

Ezra added another ring to the formation.

Then he inserted symbols that would reinforce the internal pressure resistance.

His eyes moved quickly between the notes and the circle.

Time began slipping away quietly.

The light coming through the tall library windows slowly changed.

The warm afternoon glow faded into the pale color of evening.

Candidates who had briefly entered the library left one after another, until the place returned to its earlier silence.

Ezra didn’t notice.

He was still writing.

The alchemy circle grew more complex with every addition.

More symbols, more connecting lines.

The barrel structure connected to the recoil system.

The recoil system connected to the receiver frame.

Each part had to interact correctly or the entire formation would collapse during the transformation.

Ezra leaned even closer to the page, his eyes focused and sharp.

The scratching of his pen continued.

Eventually, footsteps echoed from the far side of the library.

A voice followed.

"Library closing time!"

The announcement broke the silence.

Ezra blinked.

For a moment he looked confused, as if waking up from deep thought.

He raised his head and glanced around.

The room was nearly dark.

The last rays of sunlight had already disappeared behind the tall windows.

Ezra exhaled quietly.

"So late already..."

He gathered his papers quickly, stacking the jotter and loose sheets together before placing them inside his space bag.

But that didn’t mean he was done.

Not even close.

He left the library and walked back to his room.

Inside, the bright light of a lamp replaced the library’s quiet glow.

Ezra sat down again on the chair and placed all the papers and jotter on the table form the space bag, he took out the pen and continued working.

The night passed slowly; Symbols, Lines, Corrections.

Sometimes he paused only to stretch his fingers before continuing again.

Sleep never came.

When the faint grey light of dawn appeared outside the tent, Ezra was still working.

Morning passed without him realizing it.

By the time the sun climbed higher in the sky and the afternoon slowly approached...

Ezra finally stopped.

He leaned back slightly.

The pen slipped from his fingers and rolled onto the table.

In front of him, the complete alchemy circle for the Barrett rifle filled the entire page.

Every section connected perfectly, every symbol aligned.

Ezra stared at it for a moment.

Then he let out a quiet breath.

It was finally finished.