I borrowed this preproduction model from FN Specialties. If you want to use a can on your MK3 you'll need a barrel with threads to clear the revised cover. I would assume Jarvis will update their offering soon. I did experience mediocre accuracy while testing this barrel, but it could have been because it was a pre-production sample. I did note my bore brush passed a little easier through it vs the OEM barrel.
EFK Fire Dragon FN Five-seveN MRD MK3 5.5" Barrel