Type 56 (one of those produced with an unthreaded muzzle) and K-50M, weapons typical of North Vietnamese and NLF forces during the Vietnam War.

Edit: Apologies for changing the tags technically counter to this, but I've always lumped Type 56s (and similar AK clones with different designations like the AMM and MPi-K) under the ak-47 tag, since they all look very similar.