+1-800-504-5897 Help Center Check Order Status
About Us Policies Reviews How To
Free Shipping & Free Returns*

FREE SHIPPING on Over 250,000 Products

Shop now and get Free Value Shipping on most orders over $49 to the contiguous 48 states, DC, and to all U.S. Military APO/FPO/DPO addresses.

Enjoy our FREE RETURNS

We want to ensure that making a return is as easy and hassle-free as possible! If for any reason you are not satisfied with your purchase, simply return the item within 30 days of receipt, and we'll cover the cost of return shipping. Learn more about our Return Policy.

  • Entire Store
  • ...
  • Apparel & Footwear
  • Astronomy
  • Everything Else
  • Eyewear
  • Hunting Gear
  • Lab Equipment
  • Military Gear
  • Outdoor Gear
  • Photography Equipment
  • Police, EMS & Fire
  • Shooting
  • Sport Optics
  • Sports & Hobbies
TIP
Shopping Cart

Reviews & Ratings for TANDEMKROSS Tandemized Ruger Mark IV and Mark IV 22/45 Cthulhu Lower — 14 reviews

(14 reviews)
TANDEMKROSS Tandemized Ruger Mark IV and Mark IV 22/45 Cthulhu Lower
TANDEMKROSS Tandemized Ruger Mark IV and Mark IV 22/45 Cthulhu Lower
As Low As $636.49 Save Up to $41.50
View Product
Write a Review
Compare (0)
1 item has been added
Add at least two items to compare
Most Helpful Positive Review Ruger 22/45 Lower in Aluminum is the way to go
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 assembled with ALL of the TandemKross bits and pieces to make it great. Victory trigger, extended mag release, larger slide stop/release, thumbrest safety and a thumbrest for your offhand too, made by Strickland, plus TandemKross's hive grip, which feels great. Also worth noting is the slide stop pin that sticks up in the back is fully aluminum and no...
Read More...
Show
Sort by
Filter by

very nice lower

by camarovoodoo, Verified Owner from LA, United States Written on June 18, 2026
If using a Valquartsen upper with this lower the bolt guide plate retaining screw on upper must be filed down too clear magazine blast shield other than that the lower feels and shoots amazing
Would recommend: Yes
Was it helpful to you? Yes | No
Share

Game Changer

by Pat, Verified Owner from CA, United States Written on May 31, 2026
Bought this Lower for my wife. We love everything about it and now looking to order another for me! It is well designed and very comfortable. If you are looking for more accurate shots, this lower is a must!
Would recommend: Yes
Was it helpful to you? Yes | No
Share

Totally worth it

by BowlingPinReaper, Verified Owner from CO, United States Written on May 9, 2026
If you have a Mark IV you might as well just get this upgrade. I competitively target shoot for fun and this upgrade makes the Mark even better.
Would recommend: Yes
Was it helpful to you? Yes | No
Share

22/45 race gun lower

by ELEMENT 3 GUNWERKS, Verified Owner from AZ, United States Written on January 3, 2026
Best pound for pound knock out when it comes to anything with the 22/45 this paired with the volquartsen mamba barrel is a same hole race gun on the market tandem Kross didn’t this all the way right
Pros:
  • None
Cons:
  • NONE !
Would recommend: Yes
Was it helpful to you? Yes | No
Share

Custom Build Bonus

by Aaron., Verified Owner from OH, United States Written on 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 is flawless and all around could not be happier. The price is high but if you were to piece out each part this frame does save you some money.

Word of warning, this frame does not have the quick detach takedown button and instead ops for an allen head set screw to secure the upper and lower.
Pros:
  • Fit & finish
  • Conformable
  • Build / Quility
Cons:
  • Price (a little steep!)
Best Used for:
  • Target & Competition Shooting
Would recommend: Yes
Was it helpful to you? Yes | No
Share

Tandemkross 22/45 complete lower.

by Rick, from TX, United States Written on May 24, 2025
Beautifully machined. Works great. Fits like a glove and operates flawlessly.
Pros:
  • quality machined part
Cons:
  • None
Would recommend: Yes
Was it helpful to you? Yes | No
Share

Tandemkross 22/45 complete lower

by Rick, from TX, United States Written on May 17, 2025
Excellent. Crisp trigger. Nicely finished. Very pressed with my purchase.
Would recommend: Yes
Was it helpful to you? Yes | No
Share

Best mark iv lower

by Jm, Verified Owner from WA, United States Written on 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.
Would recommend: Yes
1 of 1 found the following review helpful.
Was it helpful to you? Yes | No
Share

All the bells and whistles

by Tony, Verified Owner from AR, United States Written on November 27, 2024
Take your .22 to a whole new level! Awesome design, feel, and function. Great customization options.
Pros:
  • all of them
Cons:
  • None
Would recommend: Yes
Was it helpful to you? Yes | No
Share

Tandemkross Cthulhu

by Ben, Verified Owner from NC, United States Written on November 27, 2024
The fit and finish is great on the lower. Locks up tight with my upper and the trigger feels great.
Would recommend: Yes
Was it helpful to you? Yes | No
Share
There are no reviews that match your criteria. Would you like to review this product?