Those are actually Sturmgewehr 44's.
For some reason you can see a lot of german World War 2 equipment in japanese mangas and animes.
In Europe they are strongly avoided, so it's pretty funny to see them appear here and there
Honestly, pretty lame to actually let them be succesfull, only to then have villains in the higher power tier appear just so they can be safed by a hero with a higher power tier.
Invalidates the entire struggle
Why even waste all that time with this planning if the elf guy who's pal with the BBEG will just do everything because everyone who can do anything right in this story can be counted on one hand after cutting a finger or two?
If it was going to result in this mentor elf guy doing everything, then we could've just focused on him as he makes his way.
Hell, it's been a while so I don't even remember if he made ANY intention of partaking in this fight.
Which is why One Piece instead has each member of the Straw Hat Crew face one member of the evil team rather than have Luffy just solo everyone after they were all beaten to a pulp.
Or have battles where creativity wins.
Like, oh, this guy can make things rust, which means Zoro's in trouble. So just have Usopp shoot him, cuz he can't rust that.