Hands on with the Ultradyne UD3 Chassis

We’ve previously featured Ultradyne’s UD7 chassis with Cerakote. This time, we’re looking at this chassis in its most compact form—the UD3.


Ultimate Reloader LLC / Making with Metal Disclaimer: (by reading this article and/or watching video content you accept these terms). The content on this website (including videos, articles, ammunition reloading data, technical articles, gunsmithing and other information) is for demonstration purposes only. Do not attempt any of the processes or procedures shown or described on this website. All gunsmithing procedures should be carried out by a qualified and licensed gunsmith at their own risk. Do not attempt to repair or modify any firearms based on information on this website. Ultimate Reloader, LLC and Making With Metal can not be held liable for property or personal damage due to viewers/readers of this website performing activities, procedures, techniques, or practices described in whole or part on this website. By accepting these terms, you agree that you alone are solely responsible for your own safety and property as it pertains to activities, procedures, techniques, or practices described in whole or part on this website.

About the Ultradyne UD3 Chassis

There are three different models of the UD Chassis: the UD3, UD5, and UD7.

Our .308 Shorty was born in a Foundation Stock and designed to be compact and versatile. A UD3 chassis just made sense.

From Ultradyne USA:

The Ultradyne Chassis is crafted from a solid bar of 6061 T6 Aircraft Aluminum for exceptional strength and durability. The one-piece design weighs between 1.1 and 1.3 pounds, depending on the model. This makes it suitable for both hunting rifles that weigh as little as 6 pounds and long range target rifles that weigh up to 16 pounds. When paired with the Ultradyne Adjustable Butt Stock, it is lighter than most factory stocks yet has the ability to add up to 5 pounds with optional weights.

The Ultradyne Chassis is packed with features including an adjustable magazine release lever, compatibility with AICS magazines, ability to work with any Mil-Spec butt stock, a built-in Arca rail, M-LOK slots on three sides, and Dynalock technology to ensure a secure fit. The action is held in place with V-channel bedding that can accommodate free-floated barrels up to 1.35 inches in diameter.


    • 6061 T6 Aluminum
    • Cerakote Finish
    • Butt stock Interface: Mil Spec
    • Grip Interface: Mil Spec A2
    • Magazine Interface: AICS
    • 1.35” Max. Barrel Diameter


    • 17 oz
    • 15.3” Length, 4.2” Arca Length
    • 8 M-LOK Slots

What’s in the Box

I received the UD3 backbone with three mounting slots in one box along with action screws, mag release, mag catch assembly, Allen keys, a sticker, and some printed materials. This chassis accepts any AR-style grip and buttstock, making this platform particularly affordable and customizable. It has M-Lok, ARCA, and Dynalock all integrated. 


I paired the UD3 with an adjustable AR buttstock I had lying around along with a Hogue grip.

Installing the barreled action came last. I used the Orange Vise and Area 419 barrel change jaws to keep everything in place.

Lastly, I added a Magpul 10-round AICS magazine and MDT GRND-POD.


I left the rifle with many of the same accessories including Hawkins DBM and Hunter Mag, a Silencer Central BANISH Backcountry suppressor, and Leupold Mark 5HD 2-10×30 scope.

I paired this with .308 tracer and subsonic loads I loaded on the Dillon RL-550C after automated case prep with the Dillon CP2000 and DA3000. The combination of Berry’s 220 grain plated bullet, Trailboss, and the Backcountry yielded near silence with the subsonic rounds.


This formula is fantastic for a truck gun. One of the great things about the Ultradyne UD3 chassis is its versatility and affordability. You can get parts from Ultradyne or use AR parts you have lying around to combine a familiar platform with the advantages of a chassis.

Get the Gear

Order and customize your UD Chassis from UltradyneUSA.com.

The UD ARCA Dynalock Rail is available separately. 

Purchase the BANISH Backcountry directly from Silencer Central.

Leupold Mark 5HD 2-10×30

Hawkins Precision DBM

Hawkins Precision Hunter Mag


Don’t miss out on Ultimate Reloader updates, make sure you’re subscribed!

Gavin Gear

Leave a Reply

Your email address will not be published. Required fields are marked *