If it is a Browning model 1910 made by F.N. they as far as I understand were never made in 9m/m parabellum. The were made in 9x17 m/m (.380 A.C.P.) and 7.65x17 m/m (.32 A.C.P.) If .380's are jamming I think you need to check the info. on the pistol and see if it isn't a 7.65 or .32 A.C.P. One other thing , .380 and 9m/m parabellum are not interchangable. In the 9 m/m family you will most commonly find the 9x17 (.380), 9x18 (Mak.), 9x19(also called luger, nato, and parabellum) and the 9x21. Each is a different caliber and do not play well with others.