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TANDEMKROSS Tandemized Ruger Mark IV and Mark IV 22/45 Cthulhu Lower Up to 10% Off Plus Blazin' Deal w/ Free Shipping — 6 models

TANDEMKROSS Tandemized Ruger Mark IV and Mark IV 22/45 Cthulhu Lower, Green/Black, TK26N0461GBY1
TANDEMKROSS Tandemized Ruger Mark IV and Mark IV 22/45 Cthulhu Lower, Black/Black, TK26N0461BBY1
TANDEMKROSS Tandemized Ruger Mark IV and Mark IV 22/45 Cthulhu Lower, Red/Black, TK26N0461RBY1
TANDEMKROSS Tandemized Ruger Mark IV and Mark IV 22/45 Cthulhu Lower, Red/Red, TK26N0461RRY1
TANDEMKROSS Tandemized Ruger Mark IV and Mark IV 22/45 Cthulhu Lower, Black/Red, TK26N0461BRY1
TANDEMKROSS Tandemized Ruger Mark IV and Mark IV 22/45 Cthulhu Lower, Green/Red, TK26N0461GRY1
TANDEMKROSS Tandemized Ruger Mark IV and Mark IV 22/45 Cthulhu Lower, Green/Black, TK26N0461GBY1
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TANDEMKROSS Tandemized Ruger Mark IV and Mark IV 22/45 Cthulhu Lower, Green/Black, TK26N0461GBY1
TANDEMKROSS Tandemized Ruger Mark IV and Mark IV 22/45 Cthulhu Lower, Black/Black, TK26N0461BBY1
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TANDEMKROSS Tandemized Ruger Mark IV and Mark IV 22/45 Cthulhu Lower, Black/Black, TK26N0461BBY1
TANDEMKROSS Tandemized Ruger Mark IV and Mark IV 22/45 Cthulhu Lower, Red/Black, TK26N0461RBY1
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TANDEMKROSS Tandemized Ruger Mark IV and Mark IV 22/45 Cthulhu Lower, Red/Black, TK26N0461RBY1
TANDEMKROSS Tandemized Ruger Mark IV and Mark IV 22/45 Cthulhu Lower, Red/Red, TK26N0461RRY1
4 of 6 images
TANDEMKROSS Tandemized Ruger Mark IV and Mark IV 22/45 Cthulhu Lower, Red/Red, TK26N0461RRY1
TANDEMKROSS Tandemized Ruger Mark IV and Mark IV 22/45 Cthulhu Lower, Black/Red, TK26N0461BRY1
5 of 6 images
TANDEMKROSS Tandemized Ruger Mark IV and Mark IV 22/45 Cthulhu Lower, Black/Red, TK26N0461BRY1
TANDEMKROSS Tandemized Ruger Mark IV and Mark IV 22/45 Cthulhu Lower, Green/Red, TK26N0461GRY1
6 of 6 images
TANDEMKROSS Tandemized Ruger Mark IV and Mark IV 22/45 Cthulhu Lower, Green/Red, TK26N0461GRY1

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Questions & Answers
FFL required to purchase and ship

The lower on a Ruger Mark 4 is considered a non serialized item so an FFL is not required. The serialized part of a Ruger Mark 4 is the barrel/ receiver portion of the firearm. The bolt is not included in the barrel/receiver and thus also does not require an FFL

by Bill, Verified Owner, July 30, 2025
See 1 More Answer
Can the blue finish part be submerged in an ultra sonic cleaner without any damage to the color or other parts in the lower? Can you answer this question?
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Customer Reviews
Helpful Positive Review Ruger 22/45 Lower in Aluminum is the way to go by Mike, Verified Owner, December 8, 2024
Built my own 22/45 using this lower and a Volquartsen upper. The TandemKross Cthulhu lower is simply incredible. Firstly, it's machined aluminum, not polymer, so tolerances and fitment are far superior and it feels great in the hand. Comes fully asse...
Read More...
1/1 found this helpful
Helpful Positive Review Best mark iv lower by Jm, Verified Owner, December 8, 2024
Super comfortable. Grip and thumb ledges are awesome. Trigger is crisp and light. Everything you would want to do to a mark iv.
1/1 found this helpful
Most Recent Reviews Custom Build Bonus by Aaron., Verified Owner, June 1, 2025
I bought this for a custom mk4 build and like the other tandemkross items I have bought before this did not disappoint. Fit and finish are excellent and it has all of the improved parts installed with no assembly required. Fit up to a Tac Sol upper...
Read More...
Most Recent Reviews Tandemkross 22/45 complete lower. by Rick, May 24, 2025
Beautifully machined. Works great. Fits like a glove and operates flawlessly.
Most Recent Reviews Tandemkross 22/45 complete lower by Rick, May 17, 2025
Excellent. Crisp trigger. Nicely finished. Very pressed with my purchase.
Most Recent Reviews All the bells and whistles by Tony, Verified Owner, November 27, 2024
Take your .22 to a whole new level! Awesome design, feel, and function. Great customization options.
Read All 10 Reviews
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Prices have been cut drastically on select models of this product as part of a special offer. These prices are so low that there's no double-dipping with coupons or any additional discounts - sorry about that. This offer won't last long, so don't miss out!
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Product Info for TANDEMKROSS Tandemized Ruger Mark IV and Mark IV 22/45 Cthulhu Lower

The #TANDEMIZED Cthulhu Lower is the single best way to get the most out of your Ruger Mark IV Standard or 22/45 pistol. What was once a stripped lower that required additional parts and assembly is now ready to host your pistols upper right out of the box! Increase the life and durability of your pistol while also increasing its reliability and performance!image

The Cthulhu Lower boasts an enlarged trigger guard for large or gloved hands, a hooked trigger guard for more points of contact, and textured backstrap for improved grip and ergonomics. Additionally, the takedown button has been replaced by a single takedown screw that helps preserve the pistols simple takedown while reducing play between the lower and upper for a firm, secure hold. The cerakoted aluminum is also less susceptible to damage from heat, chemicals, impact, or general wear and tear.

The Cthulhu Lower will support virtually any factory Ruger Mark IV or Mark IV 22/45 upper. This means the Cthulhu Lower allows you to transform any Standard Ruger Mark IV into a Mark IV 22/45! Swap your factory Mark IV magazine base pads with our Mark IV 22/45 base pads. Try either the two-pack of Tomahawk or MarkPRO Magazine Bumpers.

This upgrade contains over 30 parts, components, and accessories, all from TANDEMKROSS and all fully installed, assembled, tested, and ready to go as soon as it arrives at your door. Whether for serious competition or recreational plinking, the #TANDEMIZED Cthulhu Lower is perfect for anyone looking to improve their favorite rimfire pistol.

Specifications for TANDEMKROSS Tandemized Ruger Mark IV and Mark IV 22/45 Cthulhu Lower:

Manufacturer: TANDEMKROSS
Fabric/Material: Metallic
Gun Make: Ruger
Gun Model: Ruger 22/45
Gun Type: Pistol

Features of TANDEMKROSS Tandemized Ruger Mark IV and Mark IV 22/45 Cthulhu Lower

  • Fully metallic lower replacing factory plastic
  • Fully assembled and upgraded with all TANDEMKROSS parts and accessories
  • Drop-in ready out of the box
  • Compatible with virtually ALL factory Ruger Mark IV and Mark IV 22/45 uppers

Package Contents:

  • TANDEMKROSS Tandemized Ruger Mark IV and Mark IV 22/45 Cthulhu Lower

TANDEMKROSS Tandemized Ruger Mark IV and Mark IV 22/45 Cthulhu Lower Orderable Models

List of Orderable Models

TANDEMKROSS Tandemized Ruger Mark IV and Mark IV 22/45 Cthulhu Lower, Green/Black, TK26N0461GBY1 , MPN: TK26N0461GBY1 , UPC: 657768397707 , Code: 3GZ-PGM-TRGH-TK26N0461GBY1
TANDEMKROSS Tandemized Ruger Mark IV and Mark IV 22/45 Cthulhu Lower, Red/Red, TK26N0461RRY1 , MPN: TK26N0461RRY1 , UPC: 657768181498 , Code: 3GZ-PGM-TRGH-TK26N0461RRY1
TANDEMKROSS Tandemized Ruger Mark IV and Mark IV 22/45 Cthulhu Lower, Black/Red, TK26N0461BRY1 , MPN: TK26N0461BRY1 , UPC: 657768293160 , Code: 3GZ-PGM-TRGH-TK26N0461BRY1
TANDEMKROSS Tandemized Ruger Mark IV and Mark IV 22/45 Cthulhu Lower, Black/Black, TK26N0461BBY1 , MPN: TK26N0461BBY1 , UPC: 657768317156 , Code: 3GZ-PGM-TRGH-TK26N0461BBY1
TANDEMKROSS Tandemized Ruger Mark IV and Mark IV 22/45 Cthulhu Lower, Red/Black, TK26N0461RBY1 , MPN: TK26N0461RBY1 , UPC: 657768054723 , Code: 3GZ-PGM-TRGH-TK26N0461RBY1
TANDEMKROSS Tandemized Ruger Mark IV and Mark IV 22/45 Cthulhu Lower, Green/Red, TK26N0461GRY1 , MPN: TK26N0461GRY1 , UPC: 657768148774 , Code: 3GZ-PGM-TRGH-TK26N0461GRY1

TANDEMKROSS Tandemized Ruger Mark IV and Mark IV 22/45 Cthulhu Lower Unavailable & Discontinued Models

List of Unorderable Models

TANDEMKROSS Tandemized Ruger Mark IV and Mark IV 22/45 Cthulhu Lower, Blue/Black, TK26N0461UBY1 , MPN: TK26N0461UBY1 , UPC: 657768137266 , Code: 3GZ-PGM-TRGH-TK26N0461UBY1
TANDEMKROSS Tandemized Ruger Mark IV and Mark IV 22/45 Cthulhu Lower, Blue/Red, TK26N0461URY1 , MPN: TK26N0461URY1 , UPC: 657768158902 , Code: 3GZ-PGM-TRGH-TK26N0461URY1
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