Here you are anyone and everyone, hope this helps. If you don't see a certain rank, well obviously nothing unlocks at that point. Legendary mounts (in secondary quotations) are also included as well and they all unlock at different ranks per legendary mode level.

Rank 1
Weapon: Cattleman Revolver, Knife
Mount: El Seor

Rank 2
Weapon: Repeater Carbine

Rank 3
Weapon: Throwing Knife

Rank 4
Mount: Lusitano Nag

Rank 5
Weapon: Volcanic Pistol

Rank 8
Weapon: Winchester Repeater
Mount: Turkmen

Rank 9
Weapon: Schofield Revolver

Rank 11
Weapon: Pump Action Shotgun
[Mount: Cleveland Bay, Legendary 1 to 4 only]

Rank 13
Weapon: Springfield Rifle

Rank 15
Weapon: Dynamite
[Mount: Hungarian Half-Bred, Legendary 2 to 4 only]

Rank 17
Weapon: Double Action Revolver

Rank 18
Weapon: Sawed Off Shotgun

Rank 20
Weapon: Rolling Block Rifle

Rank 22
Weapon: Fire Bottle
Mount: Cleveland Bay
[Mount: Hungarian Half-Bred, Legendary 1 only]
[Mount: American Standard-Bred, Legendary 2 to 4 only]

Rank 24
Weapon: Semi Automatic Pistol

Rank 26
Weapon: Semi Auto Shotgun
[Mount: Bonzo (bull), Legendary 3 and 4 only]

Rank 28
Weapon: Carcano Rifle

Rank 32
Weapon: Henry Repeater

Rank 33
Mount: Hungarian Half-Bred
[Mount: American Standard-Bred, Legendary 1 only]
[Mount: Bonzo (bull), Legendary 2 only]
[Mount: Buffalo, Legendary 3 and 4 only]

Rank 35
Weapon: High Power Pistol

Rank 37
Weapon: Double Barrel Shotgun
[Mount: Albino Buffalo, Legendary 4 only]

Rank 40
Weapon: Bolt Action Rifle
Mount: American Standard Bred
[Mount: Bonzo (bull), Legendary 1 only]
[Mount: Buffalo, Legendary 2 only]
[Mount: Albino Buffalo, Legendary 3 only]

Rank 42
[Mount: Super Bull, Legendary 4 only]

Rank 43
Weapon: Evans Repeater

Rank 46
Weapon: LeMat Revolver

Rank 49
Weapon: Mauser Pistol

Rank 50
Weapon: Buffalo Rifle
Mount: Bonzo (bull)
[Mount: Buffalo, Legendary 1 only]
[Mount: Albino Buffalo, Legendary 2 only]
[Mount: Super Bull, Legendary 3 only
[Mount: Zebra Donkey, Legendary 4 only


Hope somebody finds this useful, I would've If I were new to Red Dead Redemption
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PSN ID: MercanaryWarrior

Thank You and Enjoy,
xKonvict

P.S if you need anything feel free to message me on PSN or TTG.