The 17 Aguila is a newer cartridge introduced into the market during 2004 and is based off shortening down the .22 long rifle cartridges. The bullet diameter is .172" but fits on the shell casing due to its modified reduction of the neck. The cartridge was developed in conjunction by firearm manufacturer High Standard and ammunition manufacturer Aguila in 2003.
The 17 Aguila is a varmint round designed to have less expansion on entry to do less damage to the tissue of an animal. The bullet is a 20gr jacketed solid point round that travels at 1,850 ft/s. This allows for game hunters to salvage more edible meat off a carcass. The bullet is designed to fit into a .17 Mach II (17HM2) bolt action rifle with no modifications to the rifle, or changing out the barrel on a Ruger 10/ 22.
The bullet received little attention on the market due to two other rim fires that were also released into the market by manufacturer Hornady. The .17 Hornady gained traction and took over the market in rim fire casings after their release. The 17 Aguila did gain a following after varmint hunters noticed it had less expansion that allowed for more edible meat to be salvaged on game, while still staying accurate for well-placed shots.
Although muzzleloading rifles may be found in .45-, .54-, and even .36- and .52 calibers, the most common hunting caliber is .50. The “half-inch” bore is the most flexible in terms of loads, has sufficient power potential for commonly hunted game, and offers the widest accessibility of support and maintenance equipment.
A large part of the reason for the change is the development of popular pellets (Pyrodex was first) manufactured in 50-, 30- and 20-grain capsule units.
For whitetail deer hunting, in-lines with a 1-turn-in-24 inches to 1-28 twist will deliver excellent performance with a 100-grain propellant charge and sabots in the 250- to 300-grain range. Conicals in the 300- to 385-grain range typically do very well with a similar powder charge.
A .50-caliber muzzleloader with a 1-32 to 1-38 twist rate should do well with the same sabots and conicals with a propellant charge in the 85- to 90-grain range.
A modern .54-caliber muzzleloader is almost universally manufactured with a 1-48 twist, although I have a still-serviceable 35-year-old side hammer gun in that caliber with a 1-turn-in-72 twist rate, which was good for patched round balls only. An 85- to 100-grain charge will effectively shoot .54-caliber sabots, conicals (try 425-grain bullets) and patched round balls with equal accuracy.
