One possible reason could be that Tsukishima is under some sort of mind control or influence from a more powerful and malevolent force. Maybe he has been deceived into believing that Ichigo is a threat to something he holds dear.
Ichigo might initially be in shock. He could be unable to believe that Tsukishima, who might have been a friend or at least an acquaintance, has turned on him.
Tsukishima's back story has a lot to do with family influence. His brother's success in volleyball was a big factor. He was in his brother's shadow for a long time. As a result, he was hesitant about volleyball. But as he grew in the Karasuno team, he started to find his own identity in the sport, separate from his brother.
The Barrett sniper rifle was a building block model suitable for boys over the age of six. This toy gun could be assembled into a Barrett sniper rifle model, and there were many different assembly methods to choose from. These sets contained different numbers of building blocks, and the appropriate set could be chosen according to personal preference and difficulty. However, the search results did not provide a clear answer to the question of whether the Barrett could penetrate the Lego bricks or its value.