The cookie settings on this website are set to 'allow all cookies' to give you the very best experience. Please click Accept Cookies to continue to use the site.

bolt upgrade valhalla
Catalyst Arms - Hammerhead Bolt Knob
Zoom the image with the mouse

Catalyst Arms - Hammerhead Bolt Knob

(6 reviews) Write a Review
Product ID:
Size Chart


It's always hammer down with our Hammerhead bolt knob. Large, oversized and crafted from solid aluminum the Hammerhead is designed to provide a secure grip on the bolt handle in any and all conditions. Customized with a contoured "waist" for the ergonomic ability to push the bolt knob up with the trigger finger.


Features & Benefits

  • Fits bolt handles with 5/16-24 TPI 
  • Easy installation
  • Made in the USA
  • Weight: 1.5 oz
  • Dimensions: 1"x1"x2"


Available Colors:

Black, Red


6 Reviews

  • Black Bolt Knob

    Posted by Eric on May 22nd 2019

    Well built and threaded cleanly. Not useful for a CZ 455. The lack taper makes it hit the ocular bell.

  • Great Upgrade

    Posted by RonT on Apr 4th 2019

    Installed the Hammerhead on a Ruger Precision Rifle and it is a big improvement over the OEM knob. My hand was prone to slipping off of the original part particularly when my hand was wet. With the Hammerhead, slipping has been eliminated and cycling the bolt is much easier and faster. I am very pleased with the Hammerhead bolt knob and the way it performs. I highly recommend it.

  • Excellent bolt knob

    Posted by James on Mar 4th 2019

    Feels good in they fingers while cycling rounds, helps to build a grab quickly

  • Hammerhead Heaven

    Posted by Robert Reed on Jan 17th 2019

    A perfect upgrade for function and appearance. I chose the Red to match my mag release extension and safety selector. It is large enough to ease manipulating the bolt but not so large it looks like a tumor hanging off the receiver. It is light enough not to make lifting the handle or holding the gun unbalanced.
    If you’re looking for an upgrade from stock or just looking to replace what you already have you can’t go wrong with this knob.

Write a Review

Shipping & Returns

Returns Policy
You may return most new, unopened items within 30 days of delivery for a full refund. We'll also pay the return shipping costs if the return is a result of our error (you received an incorrect or defective item, etc.).

You should expect to receive your refund within four weeks of giving your package to the return shipper, however, in many cases you will receive a refund more quickly. This time period includes the transit time for us to receive your return from the shipper (5 to 10 business days), the time it takes us to process your return once we receive it (3 to 5 business days), and the time it takes your bank to process our refund request (5 to 10 business days).

If you need to return an item, simply login to your account, view the order using the "Complete Orders" link under the My Account menu and click the Return Item(s) button. We'll notify you via e-mail of your refund once we've received and processed the returned item.

We can ship to virtually any address in the world. Note that there are restrictions on some products, and some products cannot be shipped to international destinations.

When you place an order, we will estimate shipping and delivery dates for you based on the availability of your items and the shipping options you choose. Depending on the shipping provider you choose, shipping date estimates may appear on the shipping quotes page.

Please also note that the shipping rates for many items we sell are weight-based. The weight of any such item can be found on its detail page. To reflect the policies of the shipping companies we use, all weights will be rounded up to the next full pound.

Related Products

Customers Also Viewed