As the UK Ministry of Defence prepares to replace its aging SA80 rifle family, Heckler & Koch UK is making the case for its participation in Project Grayburn.
In a recent interview with Calibre Defence, company CEO Paul McDonald discussed the firm’s current work supporting the SA80 platform and its readiness to contribute to the future rifle program.
McDonald noted that while the SA80A3 remains in service, its long-term viability is limited by the lifespan of its components—particularly the lower receiver. The officially stated out-of-service date is 2030, by which point some rifles will be more than three decades old.
Although Project Grayburn is not yet fully funded, McDonald emphasized that it must proceed to avoid operational gaps. The program is expected to cover at least 100,000 rifles and include a through-life support component extending over two to three decades.
“Heckler & Koch UK already maintains infrastructure to keep the SA80 in service,” McDonald told Calibre Defence.
He added that this foundation could be expanded into a domestic production capability, depending on the MoD’s requirements and industrial policy.
Among the options being considered by the company are the HK416 and HK433 platforms—both used by NATO allies. According to McDonald, the UK’s approach remains open-ended, with the Ministry avoiding narrowly defined technical specifications that might limit competition or innovation.
The interview also addressed the issue of caliber. While the U.S. has shifted to a 6.8mm round, McDonald suggested the UK is likely to continue with 5.56mm ammunition in the near term, due to operational realities and logistics.
One of the key points raised during the interview is that the initial batches of rifles may be sourced from overseas production lines, with UK-based assembly coming later if a domestic facility is established. Flexibility in future upgrades, including potential caliber changes, may be considered depending on system design.
McDonald acknowledged the challenge of aligning defense investment with urgent equipment needs. With multiple major programs competing for limited resources, Project Grayburn will need to demonstrate both value and readiness.
The full interview with Paul McDonald was published by Calibre Defence on August 5, 2025.

