#TANDEMIZED Cthulhu Lower for Ruger® Mark IV™ and Mark IV™ 22/45™

TANDEMKROSS

$644.99 - $689.99
(22 reviews) Write a Review
SKU:
TK26N0461
Weight:
2.50 LBS
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At a Glance:

  • Fully metallic lower replacing factory plastic

  • Fully assembled and upgraded with all TANDEMKROSS parts and accessories

  • Drop-in ready out of the box

  • Not serialized! Does not require an FFL

  • Compatible with virtually ALL factory or aftermarket Ruger® Mark IV™ and Mark IV™ 22/45™ uppers

 

The #TANDEMIZED Cthulhu 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 pistol’s upper right out of the box! Increase the life and durability of your pistol while also increasing its reliability and performance!

 

TANDEMKROSS’s Cthulhu 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 Additionally, the takedown button has been replaced by a single takedown screw that helps preserve the pistol’s simple takedown while reducing play between the lower and upper for a firm, secure hold. The cerakoted aluminum is also much less susceptible to damage from heat, chemicals, impact, or general wear and tear.

 

Since all Ruger® Mark IV™ Standard and Mark IV™ 22/45™ pistols share the same one-button takedown feature, the Cthulhu will support virtually any factory or aftermarket Ruger® Mark IV™ or Mark IV™ 22/45™ uppers. This means the Cthulhu allows you to easily turn any Ruger® Mark IV™ into a Mark IV™ 22/45™. All you need is to swap out the factory Mark IV™ magazine base pads with Mark IV™ 22/45™ base pads. TANDEMKROSS’s extended magazine bumpers perfectly fit the bill! Try either the Tomahawk or MarkPRO Magazine Bumpers that both come in packs of two.

 

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 is perfect for anyone looking to improve their favorite rimfire pistol.

 

With the #TANDEMIZED Cthulhu you’ll receive:

 

Choose your favorite color Cthulhu and all black or all red accessories! 

 

Get the #TANDEMIZED Cthulhu for your Ruger® Mark IV™ or Mark IV™ 22/45™ today and make your good gun GREAT!

 

*The Rebuild Kit comes pre-installed. The waterproof case only comes as a separate purchase of the full Rebuild Kit.

 

This product is protected against mechanical failure for life by TANDEMKROSS’s Lifetime Guarantee. Learn more about our warranty and returns policies here.

 

INTERNATIONAL CUSTOMERS: Because the Cthulhu is a frame, it is NOT available for direct international sales.

 

IMPORTANT: This product complies with ATF RULING 2009-2

Any person who installs “drop in” replacement parts in or on existing, fully assembled firearms does not manufacture a firearm and does not need to be licensed as a manufacturer under the Gun Control Act. A “drop in” replacement part is one that can be installed in or on an existing, fully assembled firearm without drilling, cutting, or machining. A replacement part, whether factory original or otherwise, has the same design, function, substantially the same dimensions, and does not otherwise affect the manner in which the weapon expels a projectile by the action of an explosive. Any person who is licensed as a dealer, which includes a gunsmith, and who installs “drop in” replacement parts in or on existing, fully assembled firearms as described in this ruling does not need to be licensed as a manufacturer under the Gun Control Act. Any person who is engaged in the business of installing “drop in” replacement parts in or on existing, fully assembled firearms as described in this ruling must be licensed as a dealer, which includes a gunsmith, under the Gun Control Act.

 

This item is NOT considered an “80% Lower” and Complies with Rule 2021 R-05F

Grandfathers in existing classifications of frames or receivers (to include split frames or receivers) and allows them to be marked in accordance with the existing requirements.

 

The full definition can be found here: https://www.atf.gov/rules-and-regulations/definition-frame-or-receiver/summary


This product is NOT a serialized part.

 


 

WARNING: This product can expose you to chemicals including chromium, which is known to the State of California to cause cancer. For more information go to www.P65Warnings.ca.gov

 

22 Reviews

  • 5
    TANDEMIZED Kraken

    Posted by Alan Nelder on 27th Jun 2022

    Just received the Kraken. It is wonderful! I mounted a Volquartsen barrel and bolt to make a great pistol. I had a couple questions and Tyler answered them immediately. I ve been dealing with Tandemkross for many years. It has been a real joy!

  • 5
    KRAKEN lower

    Posted by Scott on 18th Jun 2022

    I received the Kraken Lower a month ago and finally after a brief illness got to shoot it at a Steel Challenge match today (6-18-22). I loved it. In three of five stations I was able to improve from class c to class b. The trigger is by far the best I ve ever used and the quality and craftsmanship is fantastic. I would recommend if your looking to upgrade you Ruger Mark IV.

  • 5
    Kraken

    Posted by Jake on 15th Jun 2022

    Great quality and very comfortable and has a nice trigger. Had some trouble with light primer strikes out of the box but tech support informed me of some of the factory ruger firing pins rubbing on the recoil spring and sure enough thats what mine was doing, they got me set up with the TK titanium firing pin and it hasnt skipped a beat since! Thank you!

  • 5
    Kraken

    Posted by Dawn on 4th Jun 2022

    Works great. Handles well and comfortable.

  • 5
    Kraken

    Posted by Don Hayden on 27th May 2022

    In a word AWESOME! My first impression was that it was lighter than I expected. I love that aspect. Secondly, everything works so smoothly. I was lucky enough to score a Ruger Lite barrel from Volquartsen. I have a blue Kraken and a red barrel. Looks really sharp. I don t regret this expense at all. I own 4 Ruger Mark IV s (all with either Tandemkross or Volquartsen innards) and a Volquartsen Black Mamba. I think I like this one best. I do miss the push button disassembly feature of the factory Mark IVs, but I definitely understand why this one uses a screw. So far, I am extremely pleased with this handgun setup.

  • 5
    Kraken

    Posted by Robert on 24th May 2022

    I placed my order for the custom built kraken. They gave me a lead time of 4-6 weeks. My Kraken came in a couple weeks . I connected my kraken to my Volquartsen upper . I am super pleased with the build quality and the feel in the hand feels great . The way the kraken attaches to the upper is very confident and is rock solid . You do loose the push button take down but I think it s worth the removal of slop . I am going to be getting one more for my mini momba upper . I will say I had concerns about the trigger as I was coming from the volquartsen trigger on my rig . The feel of the kraken trigger is very much an equal to volquartsen . I would also say the volquartsen mags fit perfectly into the kraken . I was not sure prior due to the bases being much thicker . One last thing the kraken mag release button is very tactile , I had an extended release installed on my original lower but , the kraken is way better it makes my extended mag release seem so tiny . I really like the mag release on the kraken .

  • 5
    TANDEMIZED KRAKEN

    Posted by Jerry on 20th May 2022

    Worked as advertised. Probably need some basic instructions for first time assembly. Was very accurate.

  • 5
    Best 22/45 lower in the market

    Posted by Lyno Jay Sonza on 18th May 2022

    Metal!!! All internal components are form one company which will guarantee to function compatible Reliable, durable Solid!!! The best lower receiver for MK lV 22/45 MADE IN USA

  • 5
    Kraken

    Posted by Don on 13th May 2022

    This lower is fantastic. When coupled with the forward thumb ledge it causes your grip to be very consistent. It is very well made and a pleasure to shoot. I've had several folks in my shooting group try my Kraken. One has asked for the information to order one of his own, another who is a shooting instructor for a living is also considering purchasing one.