What the OP may be referring to is that reloading, and ammo selection in general, for the FN49 carries some cautions to reduce the risk of out-of-battery incidents, especially in the Egyptians which didn't come with a firing pin safety stop (FPSS).
Conventional wisdom suggests ensuring the FPSS is in place on a rifle so-equipped, that the rifle has a two-piece (rather than a one-piece) firing pin, that firing pin protrusion be checked and that harder milspec primers such as the CCI 34 be used in all reloads (CCI 250 or 200 as next best alternatives). Primers in factory ammo may be soft enough to be set off by the returning bolt before the bolt is in battery.