Going to go against the grain here.
Boys liking 'violent' things like guns, fighting, wrestling, swords, etc. is no problem at all.
I don't think fortnight is great for a 7 year old, but that is more because of the nature of, especially online, gaming, rather than the presence of guns and fighting.
Boys like fighting.. guns are fascinating for them, swords, knights, soldiers, tanks etc. They have all been fascinating to generation after generation of boys who have played Faught, Had tin soldiers, turned sticks into swords, copied wrestlers, pretended to be super heros who fight badies etc.
It is no problem at all, and perfectly natural for young children, especially boys.
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It does not correlate with violence or criminal behavior later on. I live in another country, where kids playing with big toy guns is much more normal, and yet violent crime and physical attacks here are considerably lower. Also study after study has shown no link between video games and violence. Same with violent movies.
The key is all in the framing. Superhero films do this great - yes they are violent, but it is all for protecting and saving people. Same with the army (in a kids eyes) where is all for helping and defeating bad + evil, not for doing evil.
Combative and violent play with the correct framing is actually a really essential thing for stopping boys from becoming aggressive in the future. It teaches them where violence is acceptable, gives them an outlet for their combative tendencies, and lets them be interested in swords, without actually going and hurting anyone.
So no need to ban toy guns or swords, or boys wrestling or play acting as soldiers. But just encourage them to play games where the framing is saving protecting and helping, teamwork, etc. rather than in a more mean and bullying manner.