NEW Ultradyne Picatinny Chassis + Ruger American 223

Ultradyne just launched their next generation chassis! We cover the new UD6 Picatinny Chassis end-to-end and add a Gen 2 buttstock to upgrade a Ruger American 223 bolt action.

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About the UD Picatinny Chassis

The UD Picatinny Chassis takes the features and performance of the UD chassis but with a 1913 Picatinny rear mounting interface.

This allows for even greater versatility in ease to swap buttstocks as well as increased ergonomics. This design allows quick detachment and reattachment of a buttstock for tight storage without compromising zero!

Ultradyne used to offer chassis in varying lengths with three, five, or seven M-LOK slots. The new Picatinny chassis has two options to choose from: three or six.

I opted for the UD6 for this project. Ultradyne also offers a spigot that further extends the chassis ARCA rail, allowing bipods to be mounted further forward for greater stability.

The new UD chassis has a slightly different profile, but retains the same full-length ARCA rail with Dynalock and barricade stop of the original.

The magazine release has also been redesigned for a more streamlined appearance.

Ultradyne continues to offer several different inlets: Ruger American SA, Savage SA, Rem 700 SA and clones, and Ruger 10/22.

From Ultradyne:

All the performance of the UD Chassis, now with a 1913 Picatinny rear mounting interface for instant-detach stocks and next-level ergonomics.

The UD Picatinny Chassis takes the proven platform of the UD Chassis, and replaces the traditional buffer-tube interface with a robust, rear Picatinny mounting interface so the buttstock detaches quickly for compact transport or tight storage without compromising repeatable return-to-zero. The chassis accepts our new adjustable grip system so shooters can customize trigger-finger distance to their preference, and the adjustable thumb rest lets you tune positioning for repeatability and comfort.

General:

- 6061 T6 Aluminum
- Cerakote® Finish
- Stock Interface: 1913 Picatinny
- Grip Interface: Mil Spec A2 OR UD Adjustable Grip
- Magazine Interface: AICS
- 1.35” Max. Barrel Diameter

UD3 Short Action:

- 18.5-20.2 oz depending on inlet
- 16.625” Overall Length, 6.9″ Forend/Arca Length
- 9 total M-LOK Slots

UD6 Short Action:

- 21.1-22.8 oz
- 21.35” Overall Length, 11.8″ Forend/Arca Length
- 18 total M-LOK Slots

About the Project

One size doesn’t fit all. My factory Ruger American 223 comes in a non-adjustable stock with two sling swivel studs.

It has no easy way to attach any of the ARCA accessories we love here at Ultimate Reloader or to fine-tune a cheek weld. I also want to add a muzzle device, so I employed my sporter barrel threading technique to make it possible!

Muzzle Threading

The first step was to remove the Ruger barreled action from the polymer stock and thread the muzzle.

Such a thin profile barrel required me to cut the barrel down from 22” to 19” using my Precision Matthews band saw before threading it on my PM-1440GT-VS lathe.

This lathe’s large spindle and shorter capacity allowed me to secure the entire barreled action in the lathe, complete with trigger!

About the PM-1440GT-VS

I have loved the Precision Matthews 1440GT for years, and adding variable speed only made it better! Key features of the PM-1440GT-VS include:

Variable speed
3-Speed Range Gear Box
All Taiwanese built with Japanese spindle bearings
2.055″ thru-spindle capacity
14” swing, 40” between centers, 1” follow rest capacity
D1-5 Chuck Mount
MT3 Tailstock Taper

If you’d like to know more about the PM-1440GT-VS, check out our full overview HERE.

Assembly and Shooting

I employed the Arrow Products Rock Vise to assemble the complete chassis.

This vise allows for smooth manipulation of whatever you are working on, at whatever angle you need it!

I paired the UD6 Picatinny chassis with the versatile, folding Picatinny Gen 2 buttstock.

I also added length of pull spacers, a bag rider, thumb shelf, spigot, and adjustable vertical grip.

The UD chassis was specifically designed for compatibility with the UD adjustable vertical grip.

This grip allows you to fine-tune your “trigger” length-of-pull to customize proximity to the trigger.

I used all four spacers to maximize length of pull to accommodate my long arms.

Installing the Ruger American barreled action required removing and reinstalling the mag catch.

Ultradyne’s design made this process quick and painless. Ultradyne also included the proper length action screws.

It’s important to note that I observed zero movement or flex with the foldable Gen 2 Picatinny buttstock or spigot. Both pieces are extremely robust!

A set of Athlon rings proved compatible with the Weaver rail I had on hand for this project.

I combined these with an Athlon Ares BTR Gen 2 4.5-27×50.

I obtained a 100-yard zero with Berger factory 223 ammunition and collected velocity data before heading to the Ridgeline to engage further targets.

Only one steel rock chuck remained standing at 335 yards after the “carnage” of a previous range session. (I accidentally shot one off the hanger.)

It felt wonderful to shoot this complete, upgraded rifle. I hit the lonely rock chuck over and over again at 335 yards before shooting some others off a tank trap to test my positional shooting skills.

Conclusion

Ultradyne’s chassis system is modular, yet affordable, allowing you to transform common, budget rifles into far more capable precision tools.

I was very pleased with the refinements and updates Ultradyne made to this Gen 2 chassis, particularly the simplified UD3 and UD6 options and Picatinny buttstock attachment.