In performance, the new 9.3x66 Sako cartridge is in-between the existing 9.3x62 and 9.3x64 Brenneke. Factory load ballistics call for a 286 grain bullet at a muzzle velocity (MV) of 2559 fps. This compares to a factory load MV of 2360 fps for the 9.3x62 and 2650-2690 fps for the 9.3x64 with the same weight bullets. Whether the world is clamoring for yet another 9.3mm cartridge is a moot point.

The 9.3x66 is based on a case with a standard .473" rim diameter and the new Sako creation has an overall cartridge length of 3.34". This makes it adaptable to rifles with standard (.30-06) length actions. Other particulars of the new cartridge include a case length of 2.59", a base diameter of .470", a 34 degree shoulder angle and a shoulder diameter of .450". Bullet diameter is .366" (9.3mm). Visually this is a typical modern rimless cartridge with a short neck, minimal body taper and a sharp shoulder.

Thus far Sako has not seen fit to offer 9.3x66 rifles and ammunition in the U.S., although I have read that they are selling moderately well in Europe. None of the major U.S. reloading manuals include the 9.3x66mm Sako, so trustworthy reloading data is hard to come by. In addition, reloading dies would probably have to be custom made. If I were developing loads for a 9.3x66 rifle, I'd probably start with recommended 9.3x62mm loads and work up from there, chronographing and watching carefully for signs of excess pressure as I went.

The 9.3x66 has a very small shoulder and the reloader must be careful to maintain proper headspacing during the resizing operation. This is why the other modern medium bore cartridges, such as the .338 Win. Mag., .358 Norma Mag. and .350 Rem. Mag. all use a belted case. Any of these cartridges are probably a safer choice for the casual reloader than the 9.3x66 Sako.

Note: There is a full length article about the 9.3x66 on the Rifle Cartridge Page.