Bryon Hargis

Co-Founder & CEO Castelion

[Bryon Hargis @hargsb]

Thanks to the support from the @DeptofWar, we plan to continue to expand our production capacity in New Mexico and beyond.

[Castelion @Castelion]

Project Ranger is moving fast.

17 buildings built. 1.6 million cubic yards of earth moved. 300 workers on site.

Speed matters, and we're doing our part to rebuild the Arsenal of Freedom.

[Bryon Hargis @hargsb]

I learned from a documentary that, "pointy is scary," it said nothing of the size.

It was also desired that the fully assembled weapon fit on the weapons elevator such that it did not have to be assembled on the deck. Don't worry, we are developing a larger weapon. (Will still be pointy)

[a16z @a16z]

The 2026 American Dynamism 50 is here: our annual list of 50 companies, from within the a16z portfolio and beyond, building for America's future.

This year's theme is Production is Deterrence. "America's ability to prevent conflict depends on what it can build, how fast it can deliver, and how long it can keep going."

A new generation of defense companies is moving from prototypes to full-scale production, and the industrial base has to keep pace. This year's list is organized around three pillars:

1. Systems: the drones, ships, missiles, aircraft, and spacecraft that deter conflict.

2. Factories: the plants, tools, and software that build them.

3. Inputs: the materials and power they're made of and run on.

Get all three right, and the impact reaches well beyond defense, to skilled jobs, revitalized communities, and the supply chains behind energy, housing, and everyday goods.

Meet all 50: https://t.co/vqCQtXPEBm

[Bryon Hargis @hargsb]

@grant__gregory Congrats @grant__gregory

[Bryon Hargis @hargsb]

I saw this as well so asked ai who the defense related donors to Stimson were which returned data from 2019-2024. I didn’t check the math so reader beware. Forcing everyone into a CAS is surefire way to eliminate private investments in the defense market and ensure no company spends any of their own capital on development; the opposite of what taxpayers want.

[Bryon Hargis @hargsb]

@ssb168 @Castelion I got you!

[Bryon Hargis @hargsb]

@ssb168 @Castelion Waiting for Govt approval to do so. We will if approved but thus far this photo only, sorry.

[Bryon Hargis @hargsb]

Congrats to the @Saronic team and all the builders out there!

[Vice President JD Vance @VP]

VP Vance at Saronic groundbreaking in Texas:

"What this facility represents to me is the American Dream renewed. And an American Dream built by American workers, created by American companies, and ensuring that the next generation of America's future is in our hands."

[Bryon Hargis @hargsb]

@AWeirdPhysicist You misunderstand SAR of fast moving objects.

[Bryon Hargis @hargsb]

Building Blackbeard is possible because of the @DeptofWar's commitment to building low-cost munitions at scale. Thanks @BretBaier and @SpecialReport for having me on.

[Special Report @SpecialReport]

BOLSTERING THE DEFENSE INDUSTRIAL BASE: @BretBaier examines efforts to overhaul the defense industrial base through stable, multi-year funding frameworks and a growing reliance on agile commercial startups. As Under Secretary of War for Acquisition and Sustainment Michael Duffey notes, multi-billion-dollar deals with prime contractors like Raytheon, Lockheed Martin, and Northrop Grumman are locking in production for critical systems like Tomahawk, THAAD, and Patriot interceptors. Meanwhile, the Defense Innovation Unit and next-gen tech firms like Castelion and Rocket Lab are utilizing rapid commercial manufacturing practices to scale up hypersonic capabilities and outpace modern threats.

[Bryon Hargis @hargsb]

@TheRealTomWilso @NAVAIRNews @USPACOM @CENTCOM @PAEAviation Yes, ideally Top Gun 3

[Bryon Hargis @hargsb]

@NAVAIRNews @USPACOM @CENTCOM @PAEAviation Incredible shots! 📸 📸 @Castelion is honored to be onboard.

[Bryon Hargis @hargsb]

@Castelion is honored to be the first @PAEAviation RCC project within the Department of the Navy Rapid Capabilities Office.

https://t.co/68E9yHhatU

[Bryon Hargis @hargsb]

@ZooniThusoo While I love a good panel, I can’t commit to more. Plate is fairly full.

[Bryon Hargis @hargsb]

It is an honor to be trusted to deliver next-generation air power to the fleet, with the support of the various centers and our other Navy partners. This effort anchors initial production and enables us to move forward with definitive agreements with our suppliers.

https://t.co/tWrpB4UXsR

[Bryon Hargis @hargsb]

Excited to make this demo happen. Couldn’t agree more on demonstrating capability and working with like-minded companies. We have to hit some priorities on our three platform integration contracts (one to be announced soon), but we’ll make this happen ASAP.

[Molly O’Shea @MollySOShea]

.@Saronic is partnering with @Castelion to launch a hypersonic missile off the back of an autonomous ship:

“We're actually going to launch a hypersonic missile off the back of Marauder, an autonomous ship, before the Navy completes their first test of a hypersonic missile off of a manned vessel.”

@hargsb @MavrookasD

[Bryon Hargis @hargsb]

Great to be on @DWeisburd, enjoyed chatting through how we got to today on multiple fronts.

[David Weisburd 🚀 @DWeisburd]

In 2022, an investor drew Bryon Hargis a two-by-two matrix and put his company in the corner he called impossible. Over a hundred rejections followed. Today that company is valued at $13 billion.

@hargsb, Co-founder and CEO of @Castelion , just closed a $1 billion Series C co-led by JPMorgan, Carlyle, and Andreessen Horowitz. But the more interesting story is what almost didn't happen. In the winter of 2022, after leaving @SpaceX to build hypersonic weapons, he was selling his 401k to make it through the month while his wife was expecting their second child.

Here is how he described the rejection that stuck with him:
"There was commercial, defense, software, hardware. He's like, you're on the quadrant of defense hardware, and not even in the middle of the quadrant. You're on the very corner. He's like, that's the realm of impossibility."

He still remembers the exact phrase one investor used to describe the category: in the realm of the uninvestable.

The market had not mispriced the technology risk. It had mispriced its own model. A decade of software-era venture had optimized for capital-light, fast-iterating businesses, and defense hardware failed every filter in that model: long cycles, heavy capex, a single customer with byzantine procurement. None of that made the category actually unfundable. It just made it invisible to investors running the wrong checklist.

The turning point came less than a year later, when Andreessen Horowitz wrote a check. Doors that had been closed for a year opened within days. The technology had not changed. The willingness to underwrite it had.

The lesson is not that defense tech is hot now. It is that the biggest returns tend to sit exactly where the standard model says not to look.

We’d like to thank @AlphaSenseInc for sponsoring this episode!

Full episode below 👇
https://t.co/cg93PLL2RJ

[Bryon Hargis @hargsb]

First 10 checks into Castelion by date of wire.

1) SpaceVC
2) D. D.
3) S. R.
4) T. O.
5) W. H.
6) J. B.
7) J. H.
8) Foundry Square
9) Myself
10) J. S.

Will let people self identify if they desire. 2/3 of the total SAFE was funded by myself and another employee. Best investment I’ve ever made.

[Bryon Hargis @hargsb]

Congrats Jonny and the Muon team!

[Space Capital @SpaceCapital]

Big milestone for SC funded @MuonSpace, which has closed an oversubscribed $250 million Series C, bringing total equity funding to $386 million+.

The capital will help Muon scale constellation production and expand the Mission Foundry behind its next generation of space infrastructure. 11 satellites deployed. 100% mission success. 50+ more in development.

Congratulations to CEO Jonny Dyer and the entire Muon team on what's next.

More on the Series C: https://t.co/AIiqGP8j4e

[Bryon Hargis @hargsb]

Thanks for having me on the show @MorganLBrennan

[Morgan Brennan @MorganLBrennan]

.@Castelion just raised +$1B in a series C valuing the defense tech startup at $13B, (up from $2.8B in December).

@hargsb says the capital will go toward “supercharging” production of the company’s first hypersonic weapon, Blackbeard, for which delivery begins next year. Development of a longer range hypersonic weapon and defensive systems are also in the works.

[Bryon Hargis @hargsb]

Deterrence depends on unapologetic American strength: weapon systems adversaries fear, produced in quantities they can't imagine, at a price taxpayers can afford.

Grateful to our Series C investors who are trusting us with the significant capital required to manufacture deterrence at scale and our customers for trusting us with their mission.

Thank you for believing in us, we won’t let you down.

[Castelion @Castelion]

Castelion is proud to announce our $1 billion Series C. We’re growing fast and our mission hasn't changed: build the weapons required to deter the next major war, affordably, rapidly, and at massive scale.

This funding accelerates Blackbeard production, develops a longer-range strike system, and starts work on defensive systems.

Thank you to @JPMorgan Chase's Strategic Investment Group, @a16z, @OneCarlyle, @lightspeedvp, @LavrockVC, @AltimeterCap, @TRowePrice, @generalcatalyst, and #Interlagos for backing that work. https://t.co/uvzyUWRH2S