The projekt Utskjutning (Launch) has worked on development of usable methods for computation av interior and intermediate ballistic processes. Focus has been on computations of recoil and the function of muzzle brakes, but to that aim the entire chain of specication of weapon and ammunition, via thermochemical and thermodynamical modelling as well as computational uid dynamics has been used. Method and equipment have been developed to measure the recoil of ne calibre weapons. Finally, the computational methods has been presented at the international symposium on ballistics and results from experiments and computations have been compared with satisfying agreement.