That's why I included the 18 in there. It used folded steel, which most of their weapons did already. But the 15 is actually more reliable than the 18 or sks in muddy environments, because the charging handle at the rear prevents most ingress of mud and gunk. Plus, the lighter bullet allows for more ammo capacity, something that's vital when everything they had was carried on a soldier's back or horse carts. By the end of the war, they had even run out of lead for bullets, something a smaller faster bullet might forestall.