Sierra .25 90G Hollow Point Boat Tail (100PK)GameKing. The 90 grain #1615 Hollow Point Boat Tail bullet was designed originally as a varmint bullet, but it has taken on an expanded role. This bullet is extremely accurate at all velocity levels, making it suitable for the entire range of 25 caliber cartridges. It will perform as a varmint bullet at high velocities, but it may also be used on medium game from smaller capacity cartridges, such as the 250 3000 Savage and 257 Roberts.