『The self-loaderautomatic one had a difficult internal structure not suitable to make for the first time.』
『A revolver has fewer parts compared to a semi-automatic pistolThere were fewer revolver parts compared to automatic ones.』
『The revolver was sturdier; Jams were a non-issue and the weapon was easy to maintain, making it suited for the Japanese police forces, who would rarely, if ever, have an opportunity to use their gun.there were no worries about bullet jammings and the maintenance was also easy(therefore it was suited for the japanese police who rarely used a gun).』
Based on the 3 mentioned points above, it was more suitable first work.