" . . . [Tarrant] chimped out with a semi-automatic rifle at the Al-Noor Mosque in Christchurch. . . "
No, he didn't use a semi-automatic rifle. He used a replica airgun, of the type produced by Replica Airguns. (See their website.) These "weapons" are made to look realistic, but are actually little more than toys. They are powered by a canister of CO2 that fits into the stock, and fire paint balls, pellets or blanks. I think Tarrant fired blanks. That's why, when he fired at a "body" (actually a mannequin) from only a few feet away, the "shot" did no more than ruffle the clothes or make the hair fly.
Interestingly, the mannequin in the gutter outside the mosque somehow lost her head after being "shot" by Tarrant. A later photograph, which I have on my website, shows Muslim convert Nathan Smith sitting beside the "body" and supposedly comforting it, while cops stand around. But the mannequin's head, which is clearly visible in the so-called live stream, has gone, and we see only a metal or plastic tube protruding from the torso. It's all quite bizarre.
No one died in this "shooting". If there were any deaths, they were caused in some other way at some other time. At least two researchers claim there were no fatalities at any stage, and that the bodies needed for funerals were shipped in via what is known as the "coffee run" - presumably an allusion to the color of a corpse. Unfortunately, the whole system is now so corrupt, we will probably never know the truth. Don't hold your breath while waiting for one of the inept Muslim crisis actors to spill the beans.