--- title: "Far More Powerful B61-13 Guided Nuclear Bomb Variant Joins U.S. Stockpile" description: "U.S. officials say adding the B61-13 bomb to America's nuclear arsenal is key to holding certain underground and large area targets at risk." date: "2025-05-19" modified: "2025-05-19" authors: - name: "Joseph Trevithick" job_title: "Deputy Editor" link: "https://www.twz.com/authors/joseph-trevithick" url: "https://www.twz.com/air/far-more-powerful-b61-13-guided-nuclear-bomb-variant-joins-u-s-stockpile" categories: - "Air" - "Air Forces" - "B-2" - "B-21" - "Bombers" - "News & Features" - "Nuclear" - "Nuclear Bombs" - "Nuclear Policy" - "Nuclear Warheads" - "U.S. Air Force" --- # Far More Powerful B61-13 Guided Nuclear Bomb Variant Joins U.S. Stockpile ![The first production example of the new B61-13 nuclear bomb has been completed roughly a year ahead of schedule, according to the U.S. Department of Energy.]() *DOE* The first production example of the [new B61-13 nuclear bomb]() has been completed roughly a year ahead of schedule, according to the U.S. Department of Energy. The B61-13 is based on [the preceding B61-12](), but offers a higher maximum yield that U.S. officials say offers important additional capacity to hold hardened targets, such as underground command and control facilities, and ones spread across physically larger areas, at risk. The U.S. military first announced plans to develop and field the B61-13, primarily as a replacement for the B61-7 variant, in 2023. The plan had previously been for the B61-12 to supplant the B61-7, as well as the B61-3 and B61-4 versions. The B61 is America's longest-serving family of nuclear gravity bombs, and you can read more about the existing members thereof [here](). https://twitter.com/NNSANews/status/1924510933902065888 "\[The\] Pantex Plant has completed the first production unit of the B61-13 nuclear gravity bomb – designed to strengthen the flexibility and credibility of America’s nuclear deterrent," according to a social media post today from the Department of Energy, which also included a small glimpse of the weapon. "This major milestone for America's nuclear stockpile was completed a year ahead of schedule!" “Modernizing America’s nuclear stockpile is essential to delivering President Trump’s peace through strength agenda,” Secretary of Energy Chris Wright [said in a statement today](). “The remarkable speed of the B61-13’s production is a testament to the ingenuity of our scientists and engineers and the urgency we face to fortify deterrence in a volatile new age. It was my honor today to stamp the first completed unit at the Pantex Plant in Amarillo, Texas, where all the efforts of NNSA’s labs, plants, and sites culminated in this amazing milestone. This achievement signals American strength to our adversaries and allies alike.” https://twitter.com/Casillic/status/1924490845710942624 The [Pantex Plant]() in Texas is where U.S. nuclear weapons are assembled and disassembled, and the facility also oversees testing and evaluation activities. Pantex falls under the oversight of the [Department of Energy's National Nuclear Security Administration]() (NNSA), which manages the development of new and improved nuclear weapons and sustains America's existing nuclear stockpile. "NNSA anticipated achieving the first production unit for the B61 Mod 13 later this month, almost a full year ahead of schedule," Teresa Robbins, NNSA's Acting Administrator, [had told members]() of the House Armed Services Committee on May 7. Robbins' prepared remarks for the hearing said that "taking advantage of existing B61 production lines" had been a key factor in accelerating work on the new version. "Decades of B61 design and qualification data gave NNSA’s program managers and engineers from the national laboratories and production plants confidence that they could accept calculated risks to speed production," per [an NNSA press release today](). "By streamlining or in some cases combining 'design gates' – the rigorous reviews conducted at each step of a weapon design process – engineers were able to commence production far sooner than a standard schedule would allow. These efficiencies allowed B61-13 hardware 'test builds' to be manufactured just three months after the program received authorization and appropriation from Congress." From the pictures that have been released to date, it looks essentially identical to the B61-12 externally. The B61-13 notably features the same tail kit assembly (TKA) [containing an inertial navigation system (INS) guidance package]() that was introduced on the B61-12. ![]() *B61-13 test articles. *Sandia National Laboratories** ![]() *A picture of a test B61-12 loaded onto an F-15E Strike Eagle with the TKA highlighted. *DOD** In addition, "the B61-13 incorporates the same modern safety, security, and accuracy features as the B61-12," according to today's NNSA release. Yield is where the B61-13 is understood to differ most from the B61-12. All B61 variants are so-called "dial-a-yield" weapons that can be set to detonate with varying degrees of explosive force. Though the exact figures are classified, the U.S. government has said the maximum yield of the B61-13 will be in line with the previous B61-7 version it is intended to replace, the highest yield setting on which is [reportedly between 340 and 360 kilotons](). The reported maximum yield of the B61-12 [is 50 kilotons](). The B61-7 is one of the most powerful nuclear gravity bombs in the U.S. stockpile now. Despite the lower maximum yield, the U.S. military [had previously argued]() that the new guidance capability found on the B61-12, which is also spin-stabilized using small rocket motors positioned around the rear of its body for additional accuracy, would allow it to hold hardened targets, even ones deep underground, at risk by being able to focus explosive force on a more precise point. Even before the announcement of plans for the B61-13 two years ago, the U.S. government had already been steadily walking back expectations for the B61-12. https://www.youtube.com/watch?v=xhs4VQ9dN3s It's worth noting here that the B61-13 will be reserved for U.S. military use only, unlike the B61-12, which America's NATO allies [could employ via the alliance's nuclear sharing agreements]() if authorized. Interestingly, in 2022, U.S. officials confirmed that not all aircraft set to be certified to carry the B61-12, particularly certain tactical jets in NATO service, will be able to employ the precision guidance capability, as you can read more about [here](). In addition, unlike the B61-12, which U.S. F-15E Strike Eagles and F-35A Joint Strike Fighters are certified to employ, the B61-13 will be reserved for use by [B-2 Spirit]() and forthcoming [B-21 Raider stealth bombers](). U.S. B-52 bombers are [no longer certified to drop nuclear gravity bombs]() of any type, though they are still able [to fire nuclear-tipped cruise missiles](). ![]() *Air Force personnel prepare to load a B61-12 test article onto a B-2 bomber. *USAF** Overall, work on the B61-13 comes as China, America's chief global competitor and pacing threat, [as well as Russia](), have [continued]() to expand their underground military infrastructure. In addition to [new subterranean command and control facilities](), the Chinese People's Liberation Army (PLA) has notably constructed vast new fields [of new intercontinental ballistic missile (ICBM) silos]() in recent years. The PLA also has [an underground submarine base]() and [many airfields with cavernous hardened hangars](). ![]() *Details about the state of new ICBM silo fields in northern China as assessed by the U.S. military per an annual report released in December 2024. *DOD** Smaller countries like North Korea and Iran have also been increasingly pushing strategic and [other military assets](), particularly [facilities tied to their nuclear]() and [long-range ballistic missile programs](), deeper underground just in response to potential [conventional threats, primarily from the United States](). This [includes silo-based]() and [other hardened ballistic missile launch infrastructure](). At the same time, the B61-13 is not expected to be able to hold absolutely all deeply buried targets at risk. There are still no known plans for a direct successor to [the highly specialized B61-11 variant](), which features a substantially reinforced outer shell and a rocket booster in the tail to help it penetrate down toward especially deeply buried targets. Russia’s [Kosvinsky Kamen](), a key component of that country's [nuclear command and control enterprise]() that is situated under a mountain, is understood to have been a key driver behind the B61-11's development in the first place. https://twitter.com/Casillic/status/1470605862406348805 A contracting notice in January did [hint at the possibility that further B61 versions]() could be on the horizon. In the meantime, production of higher-yield B61-13s is now well underway. *Contact the author: joe@twz.com* ## Author Joseph is *TWZ’s* Deputy Editor, helping to oversee the site’s highly experienced and dedicated team, while also writing informative and impactful defense and national security content. He lives right in the thick of it in the Washington, D.C. area. ### Author social links [Twitter]() [Bluesky]()