This is a Hornady V-Max known as the Varmint Express chambered in 17 Hornady Mach 2, model 83177.
From prairie dogs to coyote and fox" the Hornady(R) Rimfire line of ammunition offers varmint hunters high speed rimfire cartridges. Loaded with either the V-MAX(R) or NTX(R) bullet" these loads deliver tack-driving accuracy and dramatic expansion on impact.
17 Mach 2
2,100 Feet per second
17 Grain V-Max
50 Rounds per box