The new XM312 machinegun, with a low rate of fire, both to make the lightweight gun more controlable and so as not to quickly expend the amount of ammunition that an infantry team can carry by hand, is also convertable to the 25mm cartridge, also used in
the new Barrett 25mm *Payload Rifle* antimaterial rifle.
The older M85 MG is not convertable to 25mm. At least not until I start tinkering with one. The 25mm ammunition wasn't available the last time I had some M85s that I could work on for that sort of project.