I wouldn't either. While these things are kind of neat from an antique perspective, they weren't very good even in their time. I've read that anti-tank rifles were basically garbage because tank armor evolved too quickly during the world wars. Some models were somewhat successful, but became obsolete very quickly.
If you want max boom, they make some modern large caliber rifles that are easier to handle and that you can actually find ammunition for.
The Germans were the only nation to get an anti-tank rifle developed and deployed during WW1. By the time WW2 rolled around, pretty much everyone had a version of one but armor tech had caught up. The rifles were still used in an anti-light vehicle capacity and found use as the direct predecessor to modern anti-material rifles (basically the .50 BMG of its day)
Knowing nothing about guns, I misread the title as "someone just invented a rifle that can take down a tank, and we're going to fire it." Naturally I'm disappointed, but it's my own fault.
Me too, I was hoping to see a small rifle shred through a tank or at least a sheet of metal or some kind of dummy or some steel drums. Still pretty cool though.