It’s a viper pst 5x25, 680 is the furthest, when I first got it, I shot it at 600 in a hunter class competition with the 130 sirrocos. I had no idea where I was hitting cause we were at 12x and ended up low but with everything inside a 5” circle. Never again as the barrel was hot even with the 2 minutes after 5 shots. I’ve got about 500 rounds through it and it will still put 4 shots inside a 1” square at 200. It’s a custom brake our gun club president made and installed.