Has everybody heard about the 17 caliber? I just found out they have a new kind of bullet that suprisingly looks like a rifle shell but it has smaller grain.

Are you referring to the 17 Hornady Mach 2? This is a regular 22 lr rimfire case necked down to accept a .17 caliber bullet. The same idea of the 17 HMR, which was the 22 Magnum case necked down take a 17 caliber bullet.


There's quite a few posts in the rimfire section of this forum discussing these.