11.3" Blackstar Barrel
Barrel
Unlocked at Weapon Level 37.
Mid-range barrel: balanced handling and range.
Weapons / SMG
Close range at LV 42: 5 of 5 final

Waiting for a verified source.
The official patch notes haven't changed this weapon yet.
We have ready builds for the RK-9: close range, long range. Pick a style and your weapon level in the lab above and we equip the right parts for that level, with stand-ins until the parts unlock.
The RK-9 maxes out at weapon level 42. After that you can enter weapon prestige and unlock its prestige attachment.
We list 46 compatible attachments for the RK-9 across 9 slots, each with its unlock level and what it does.
The prestige attachment is the MFS Ironlung Handstop. It unlocks after you reach max level and enter weapon prestige.
In the same class: CARBON 57, CBRS-3, DRAVEC 45. Each has its own page with level-by-level builds.
Barrel
Unlocked at Weapon Level 37.
Mid-range barrel: balanced handling and range.
Barrel
Unlocked at Weapon Level 3.
Control barrel: less recoil and faster bullets, slower handling.
Barrel
Unlocked at Weapon Level 11.
Long barrel: longer damage range, slower aiming.
Exact image unavailable — Rear Grip
SPECIAL CODE category presentation — not the exact attachment geometry.
Rear Grip
Unlocked at Weapon Level 19.
Sprint-to-fire grip: shoot sooner after sprinting.
Barrel
Unlocked at Weapon Level 21.
Short barrel: faster aiming and movement, shorter damage range.
Barrel
Unlocked at Weapon Level 30.
Hybrid barrel: faster bullets and more range, slightly slower aiming.
Exact image unavailable — Fire Mods
SPECIAL CODE category presentation — not the exact attachment geometry.
Fire Mods
Unlocked at Weapon Level 26.
FMJ rounds: bullet velocity and range.
Exact image unavailable — Fire Mods
SPECIAL CODE category presentation — not the exact attachment geometry.
Fire Mods
Unlocked at Weapon Level 2.
High-velocity ammo: faster bullets and more range.
Exact image unavailable — Fire Mods
SPECIAL CODE category presentation — not the exact attachment geometry.
Fire Mods
Unlocked at Weapon Level 18.
Recoil springs: less recoil.
Exact image unavailable — Magazine
SPECIAL CODE category presentation — not the exact attachment geometry.
Magazine
Unlocked at Weapon Level 6.
Extended mag: more ammo per magazine, slower handling.
Exact image unavailable — Magazine
SPECIAL CODE category presentation — not the exact attachment geometry.
Magazine
Unlocked at Weapon Level 34.
Extended mag: more ammo per magazine, slower handling.
Exact image unavailable — Muzzle
SPECIAL CODE category presentation — not the exact attachment geometry.
Muzzle
Unlocked at Weapon Level 7.
Suppressor: keeps your shots off the minimap.
Exact image unavailable — Magazine
SPECIAL CODE category presentation — not the exact attachment geometry.
Magazine
Unlocked at Weapon Level 25.
Fast mag: faster reload.
Exact image unavailable — Optic
SPECIAL CODE category presentation — not the exact attachment geometry.
Optic
Unlocked at Weapon Level 24.
Optic: a sight for clearer aiming.
Exact image unavailable — Laser
SPECIAL CODE category presentation — not the exact attachment geometry.
Laser
Unlocked at Weapon Level 4.
Steady laser: steadier aim while aiming down sights.
Exact image unavailable — Laser
SPECIAL CODE category presentation — not the exact attachment geometry.
Laser
Unlocked at Weapon Level 31.
Steady laser: steadier aim while aiming down sights.
Exact image unavailable — Fire Mods
SPECIAL CODE category presentation — not the exact attachment geometry.
Fire Mods
Unlocked at Weapon Level 39.
Eliminate all Horizontal Recoil while firing with an improved fire rate at the expense of Muzzl…
Underbarrel
Unlocked at Weapon Level 29.
Mobile recoil foregrip: faster movement with some recoil control.
Exact image unavailable — Optic
SPECIAL CODE category presentation — not the exact attachment geometry.
Optic
Unlocked at Weapon Level 14.
Optic: a sight for clearer aiming.
Exact image unavailable — Muzzle
SPECIAL CODE category presentation — not the exact attachment geometry.
Muzzle
Unlocked at Weapon Level 35.
Mobility muzzle: better hip-fire and movement speed.
Exact image unavailable — Muzzle
SPECIAL CODE category presentation — not the exact attachment geometry.
Muzzle
Unlocked at Weapon Level 20.
Compensator: less vertical recoil.
Exact image unavailable — Muzzle
SPECIAL CODE category presentation — not the exact attachment geometry.
Muzzle
Unlocked at Weapon Level 12.
Muzzle brake: less gun kick and vertical recoil.
Underbarrel
Unlocked at Weapon Level 17.
Recoil foregrip: less recoil.
Exact image unavailable — Stock
SPECIAL CODE category presentation — not the exact attachment geometry.
Stock
Unlocked at Weapon Level 32.
Aim-walk stock: faster movement while aiming.
Exact image unavailable — Rear Grip
SPECIAL CODE category presentation — not the exact attachment geometry.
Rear Grip
Unlocked at Weapon Level 10.
Quickdraw grip: faster aim-down-sights.

SPECIAL CODE
Muzzle
Unlocked from the Season 4 Battle Pass.
No verified effect summary is published for this attachment.
Exact image unavailable — Laser
SPECIAL CODE category presentation — not the exact attachment geometry.
Laser
Unlocked at Weapon Level 42.
Handling laser: faster aiming and sprint-to-fire (visible laser).
Underbarrel
Prestige
Stackable attachment that improves fire rate through reducing burst cooldown.
Exact image unavailable — Muzzle
SPECIAL CODE category presentation — not the exact attachment geometry.
Muzzle
Unlocked at Weapon Level 28.
Firepower suppressor: off the minimap, faster bullets and more range, slower aiming.
Exact image unavailable — Rear Grip
SPECIAL CODE category presentation — not the exact attachment geometry.
Rear Grip
Unlocked at Weapon Level 41.
Accuracy grip: less vertical recoil.
Exact image unavailable — Stock
SPECIAL CODE category presentation — not the exact attachment geometry.
Stock
Unlocked at Weapon Level 9.
Mobility stock: faster movement and sprint.
Underbarrel
Unlocked at Weapon Level 8.
Mobility foregrip: faster movement.
Exact image unavailable — Rear Grip
SPECIAL CODE category presentation — not the exact attachment geometry.
Rear Grip
Unlocked at Weapon Level 27.
Quickdraw grip: faster aim-down-sights.

SPECIAL CODE
Muzzle
Unlocked via Weekly Challenge Reward.
Recoil suppressor: off the minimap with less recoil.
Exact image unavailable — Laser
SPECIAL CODE category presentation — not the exact attachment geometry.
Laser
Unlocked at Weapon Level 15.
Tactical laser: faster aiming in tactical stance (visible laser).
Barrel
Unlocked via Weekly Challenge Reward.
(Bloom Calibration Barrel)
Exact image unavailable — Magazine
SPECIAL CODE category presentation — not the exact attachment geometry.
Magazine
Unlocked at Weapon Level 13.
Flip mag: more ammo and faster reloads.
Exact image unavailable — Optic
SPECIAL CODE category presentation — not the exact attachment geometry.
Optic
Unlocked at Weapon Level 33.
Optic: a sight for clearer aiming.
Exact image unavailable — Stock
SPECIAL CODE category presentation — not the exact attachment geometry.
Stock
Unlocked at Weapon Level 16.
Control stock: less recoil, slower handling.

SPECIAL CODE
Underbarrel
Unlocked from the Season 3 Battle Pass.
No verified effect summary is published for this attachment.
Exact image unavailable — Optic
SPECIAL CODE category presentation — not the exact attachment geometry.
Optic
Unlocked at Weapon Level 5.
Optic: a sight for clearer aiming.
Exact image unavailable — Laser
SPECIAL CODE category presentation — not the exact attachment geometry.
Laser
Unlocked at Weapon Level 23.
Steady laser: steadier aim while aiming down sights.
Exact image unavailable — Stock
SPECIAL CODE category presentation — not the exact attachment geometry.
Stock
Unlocked at Weapon Level 22.
Tactical stock: better hip-fire and tactical-stance accuracy.
Exact image unavailable — Rear Grip
SPECIAL CODE category presentation — not the exact attachment geometry.
Rear Grip
Unlocked at Weapon Level 36.
Stabilization grip: less horizontal recoil, slightly slower aiming.
Exact image unavailable — Stock
SPECIAL CODE category presentation — not the exact attachment geometry.
Stock
Unlocked at Weapon Level 40.
Flinch stock: less aim flinch when you get hit.
Underbarrel
Unlocked at Weapon Level 34.
Mobility foregrip: faster movement.