If you don't know how to make plugins, use the PLUGIN REQUESTS section.
well, i proof this https://forums.alliedmods.net/showthread.php?t=89510 ; change the ev_curweapon, and now i do it with hamsandwich, for the moment I tried it a lot and you can no longer "bug" the weapon, I leave the momentary solution that I found written here in case someone will be useful in the future.