the flare isn't burning long enough. 15 sec is too short. originally it lasts about 25 to 30 sec.
http://www.deutschesheer.de/portal/a/heer/start/technik/handwaffen/carlgustaf/!ut/p/z1/hU5NC4IwGP4tHbzunR-VdZsEUUhECukuMXXNYjmZy_XzMzwFSc_t-eQBChnQhvU3wcxNNUwOPKeLSxTGaeytPG9-CAK8W5B9it2Nu41cOP8L0MHGEyAYkopDPmwsJzdOASRAgd5Zz16oVdpIbhArPw8hr1lTSX5UJRmFPVAhVTFeJ03hhwKo5leuuUZPPci1MW23drCDrbVIKCUkRxV38K9GrToD2VcQ2kdmsT-XfUxmb_vNty4!/dz/d5/L2dBISEvZ0FBIS9nQSEh/#Z7_B8LTL29225N440I6AJT01D1GR4