I've noticed a few grammatical errors/inconsistencies across various items in the game. While this is far from a comprehensive list, I've noted those that I've found on some more common items.

Ballistic Vest

"Designed to reduce the impact of small-arms fire, a favourite with narco's for it's fairly low-price and high-performance."

narco's > narcos -- narco's ('narco is' or possessive) replaced by plural

it's > its -- 'it is' replaced by possessive

+the Ballistic Vest -- sentence needs a subject

low-price/high-performance > low price/high performance -- not compounds

Suggestion:

"Designed to reduce the impact of small-arms fire, the Ballistic Vest is a favourite with narcos for its fairly low price and high performance."

Covert Stab Vest

"A covert stab vest let's you feel some protection without being too bulky."

covert stab vest > Covert Stab Vest -- capitalization consistent with other mentions of items in descriptions

let's > lets -- 'let us' replaced by 'lets'

Suggestion:

"A Covert Stab Vest lets you feel some protection without being too bulky."

Full-Body Armour

"For the ultimate protective armour, look no further than this Full-Body armour. Used by the countries elite response units, it offers full protection."

Full-Body armour > Full-Body Armour -- consistency

countries elite > country's elite -- countries (plural) to country's (possessive)

Suggestion:

"For the ultimate protective armour, look no further than this Full-Body Armour. Used by the country's elite response unit, it offers full protection."

M1911

"The M1911 produced by Colt was the standard sidearm of the U.S. military from 1911 to 1985, marking one of the longest periods of a standard weapon. The M1911 was used by U.S. soldiers in World War I, World War II, Korean War, and Vietnam War."

'M1911 produced by Cold was' > 'M1911, produced by Colt, was'

Korean/Vietnam War > the Korean/the Vietnam War

Suggestion:

"The M1911, produced by Colt, was the standard sidearm of the U.S. military from 1911 to 1985, marking one of the longest periods of a standard weapon. The M1911 was used by U.S. soldiers in World War I, World War II, the Korean War, and the Vietnam War."

Glock 18

"As a true fully automatic pistol the G18 is one of the most specialized GLOCK pistols. With an eternal fire selector at the rear of the slide you can switch from semi-automatic to full-automatic firing mode. It comes with an extended 19 round magazine for extra stopping power."

fully automatic > fully-automatic -- compound adjectives

pistol the > pistol, the

GLOCK > Glock -- consistency

-pistol, +models -- pistol is redundant/repetetive

slide you > slide, you

19 round > 19-round -- compound

Suggestion:

"As a true fully-automatic pistol, the G18 is one of the most specialized Glock models. With an external fire selector at the read of the slide, you can switch from semi-automatic to full-firing mode. It comes with an extended 19 round magazine for extra stopping power."

Walther P38

"The Walther P38 is a 9mm semi-automatic pistol that was developed by as the service pistol of the Wehrmacht at the beginning of World War II. It's not going to turn any heads in the Cartel but it'll do the job."

+Carl Walther

Cartel but > Cartel, but -- compound sentence needs comma before conjunction

Suggestion:

"The Walther P38 is a semi-automatic pistol that was developed by Carl Walther as the service pistol of the Wehrmacht at the beginning of World War II. It's not going to turn any heads in the Cartel, but it'll do the job."

S&W Magnum Revolver

"The most powerful production revolver in the world was designed by Smith & Wesson. There are few revolvers in the world for renowned."

Entire sentence(s) incomplete/confusing.

Suggestion:

"The S&W Magnum is renowned as one of the most powerful mass-produced revolvers in the world. As the name suggests, this firearm was designed by Smith & Wesson."

Desert Eagle

"The fact is, you'll never feel more confident than having this shiny silver cannon in your pocket. When you've got 'Desert Eagle point Five O' written down the side what else do you need?"

'than having this' > 'than when you have' -- phrasing

shiny silver > shiny, silver -- multiple adjectives

side what > side, what -- break in compound sentence

Suggestion:

"The fact is, you'll never feel more confident than when you have this shiny, silver cannon in your pocket. When you've got 'Desert Eagle point Five O' written down the side, what else do you need?"

M16A2 Rifle

"Developed in America, the M16A2 has also been widely adopted by armed forces around the world for it's reliability and accuracy."

it's > its -- 'it is' replaced by its (possessive)

Suggestion:

"Developed in America, the M16A2 has also been widely adopted by armed forces around the world for its reliability and accuracy."

AK-47

"Developed in the Soviet Union by Russian small-arms designed Mikhail Kalashnikov, one of the most popular and widely used rifles in the world."

+subject to second part

widely used > widely-used -- compound

Suggestion:

"Developed in the Soviet Union by Russian small-arms designed Mikhail Kalashnikov, the AK-47 is one of the most popular and widely-used rifles in the world."

MG5

"Modern, modular Bundeswehr LMG made by Heckler & Koch and used primarily by German forces. With a cast steel exterior and a variable cyclic rate."

Entire sentence(s) confusing/incomplete.

Suggestions:

"The modern, modular Bundeswehr LMG was made by Heckler & Koch and used primarily by German forces. This model includes a cast-steel exterior and a variable cyclic rate."

or

"Used primarily by German forces, the Heckler & Koch Bundeswehr LMG features a cast-steel exterior and variable cyclic rate."

SIG SG 550

"Accurate and reliable as a Swiss Watch, the SIG SG 550 is used by elite and special forces units across the world. Known as one of the finest 5.56mm assault rifles ever made."

Watch > watch -- no need for capitalization here

Know...made. -- incomplete sentence, needs a subject

Suggestions:

"Accurate and reliable as a Swiss watch, the SIG SG 550 is used by elite and special forces units across the world. It's known as one of the finest 5.56mm assault rifles ever made."

or

"Accurate and reliable as a Swiss watch, the SIG SG 550 is used by elite and special forces units across the world. Known as one of the finest 5.56mm assault rifles ever made, this rifle could now be yours to use."

Steyr AUG

"The Steyr Aug is an Austrian assault rifle with a signature look. Lightweight and reliable it's a favourite of armies around the world due to its modular nature. Also great for lefties!"

Aug > AUG -- consistent/correct capitalization

reliable it's > reliable, it's

'Also great for lefties!' -- incomplete sentence, no subject

Suggestions:

"The Steyr Aug is an Austrian assault rifle with a signature look. Lightweight and reliable, it's a favourite of armies around the world due to its modular nature. It's also great for lefties!"

or

"The Steyr Aug is an Austrian assault rifle with a signature look. Lightweight and reliable, it's a favourite of armies around the world due to its modular nature. Also great for lefties, this firearm can be used ambidextrously!"

G36

"World-renowned German engineering, The G36 lacks any fancy bells and whistles, but it makes that up by being a modern, light, accurate and rugged weapon."

Entire sentence(s) incomplete/confusing.

Suggestions:

"The G36 lacks any fancy bells or whistles, but thanks to its world-renowned German engineering, it makes that up by being a rugged and modern yet lightweight and accurate weapon."

or

"With world-renowned German engineering on proud display, tthe G36 is a modern, light, accurate, and rugged weapon."

MG34

"The MG34 is a German recoil-operated LMG. Although it was arguably one of the most advanced in it's time, this particular model is definitely starting to show it's age. Spray and pray boys, Spray and pray."

it's > its -- 'it is' replaced to its (possessive)

it's > its -- samesies :3

'pray boys' > 'pray, boys,'

Spray > spray -- correct capitalization

Suggestion:

"The MG34 is a German recoil-operated LMG. Although it was arguably one of the most advanced in its time, this particular model is definitely starting to show its age. Spray and pray, boys, spray and pray."

Fragmentation Grenade

"Used primarily for infantry combat and tactical engagements, the fragmentation grenade inflicts devastating injuries to enemies unlucky enough to be caught in it's blast radius. Its effectiveness lies in its ability to strike adversaries in cover or behind obstacles, making it a formidable tool for clearing entrenched positions."

it's > its -- 'it is' replaced to its (possessive)

Suggestion:

"Used primarily for infantry combat and tactical engagements, the fragmentation grenade inflicts devastating injuries to enemies unlucky enough to be caught in its blast radius. Its effectiveness lies in its ability to strike adversaries in cover or behind obstacles, making it a formidable tool for clearing entrenched positions."

Cannabis

"Grown with love and expertise by only the most discerning narcos, carefully crafted to harmonize and create a delightful symphony of flavor and effect. With every toke, your care for the worries of the world melt away dramatically increasing your defence for a short period of time."

away dramatically > away, dramatically

Suggestion:

"Grown with love and expertise by only the most discerning narcos, carefully crafted to harmonize and create a delightful symphony of flavor and effect. With every toke, your care for the worries of the world melt away, dramatically increasing your defence for a short period of time."

Personal Favour

"The Personal Favour is granted to players by El Capo, the boss of boss's. It's a valuable asset that can be used to get the player out of jail when they find themselves in a tight spot with the law. With this favour, players bypass the usual legal processes and secure their freedom with just a single phone call to El Capo."

boss's > bosses -- 'boss is' replaced to bosses (plural)

player > narco -- optional for consistency

Suggestion:

"The Personal Favour is granted to players by El Capo, the boss of bosses. It's a valuable asset that can be used to get a narco out of jail when they find themselves in a tight spot with the law. With this favour, narcos bypass the usual legal processes and secure their freedom with just a single phone call to El Capo."

Fiat Panda

"Commonly known as a box on wheels. The Fiat Panda is the epitome of functionality over form."

wheels. The > wheels, the

Suggestion:

"Commonly known as a box on wheels, the Fiat Panda is the epitome of functionality over form."

This is awesome, thanks for taking the time to put this together Minerva. I'll review it as soon as I can and fix the issues.

Minerva is the GOAT

Thanks again for the thorough suggestion Minerva, all of your recommended changes have now been added