In This Little Guide I Will Be Posting All The Required Levels For All The Weapons And Perks And What It Takes To Get Attachments.
And My Current Level. Which Changes By The Day.

My Current Level: 55

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Primary Weapons
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Assault Rifles
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1. M16A4 - You Get It From The Start
2. AK-47 - You Get It From The Start
3. M4 Carbine - Level 10
4. G3 - Level 25
5. G36C - Level 37
6. M14 - Level 46
7. MP44 - Level 52

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Sub Machine Guns
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1. MP5 - You Get It From The Start
2. Skorpion - You Get It From The Start
3. Mini Uzi - Level 13
4. AK-47u - Level 28
5. P90 - Level 40

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Light Machine Guns
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1. M249 SAW - You Get It From The Start
2. RPD - You Get It From The Start
3. M60E4 - level 19

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Shotguns
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1. W1200 - You Get It From The Start
2. M1014 - Level 31

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Sniper Rifles
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1. M40A3 - You Get It From The Start
2. M21 - Level 7
3. Dragunov - Level 22
4. R700 - Level 34
5. Barret .50 Cal - Level 49

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Side Arms
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1. M9 - You Get It From The Start
2. USP .45 - You Get It From The Start
3. M1911.45 - Level 16
4. Desert Eagle - Level 43

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Attachments
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1. Red Dot Sight - Get 25 Kills In Totall
2. Silencer - Get 75 Kills In Totall
3. ACOG Scope - Get 150 Kills In Totall

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Special Grenades
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1. Flash Grenade - You Get It From The Start
2. Stun Grenade - You Get It From The Start
3. Smoke Grenade - You Get It From The Start

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Perks
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Perks 1
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1. C4 x2 - You Get It From The Start
2. Special...

1.

Name: Assault

Primary Weapon: G36C
Primary Weapon Attachment: Red Dot Sight
Primary Weapon Camouflage: Digital

Side Arm: Desert Eagle
Side Arm Attachment: None

Type Of Special Grenade: Flash

Amount Of Frags: 1
Amount Of Special Grenades: 3

Perk 1: Special Grenades x3
Perk 2: Stopping Power
Perk 3: Deep Impact

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2.

Name: Sniper

Primary Weapon: Barret .50cal
Primary Weapon Attachment: None
Primary Weapon Camouflage: None

Side Arm: G36C
Side Arm Attachment: Red Dot Sight
Type Of Special Grenade: Smoke

Amount Of Frags: 1
Amount Of Special Grenades: 1

Perk 1: Claymore x2
Perk 2: Overkill
Perk 3: Iron Lungs

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3.

Name: Fast

Primary Weapon: MP5
Primary Weapon Attachment: ACOG Scope
Primary Weapon Camouflage: None

Side Arm: Desert Eagle
Side Arm Attachment: None

Type Of Special Grenade: Stun

Amount Of Frags: 1
Amount Of Special Grenades: 1

Perk 1: RPG-7 x2
Perk 2: Sleight of Hand
Perk 3: Deep Impact

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4.

Name: Shotgun

Primary Weapon: M1014
Primary Weapon Attachment: Red Dot Sight
Primary Weapon Camouflage: None

Side Arm: Desert Eagle
Side Arm Attachment: None

Type Of Special Grenade: Flash

Amount Of Frags: 1
Amount Of Special Grenades: 1

Perk 1: Bandolier
Perk 2: Double Tap
Perk 3: Martyrdom

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5.

Name: Search&Destroy

Primary Weapon: M14
Primary Weapon Attachment: ACOG Scope
Primary Weapon Camouflage: None

Side Arm: Desert Eagle
Side Arm Attachment: None

Type Of Special Grenade: Flash

Amount Of Frags: 1
Amount Of Special Grenades: 1

Perk 1: Bomb Squad
Perk 2: Sleigth of Hand
Perk 3: Dead Silence