The .30-30 Ackley Improved
By Chuck Hawks
Like any "Improved" wildcat cartridge, the .30-30 Ackley is a blown-out version of the .30-30 Winchester. .30-30 cases are fire-formed by being fired in a rifle with an Improved (reamed-out) chamber, and a .30-30 Improved case is the result.
The improvements thus achieved include a case body with less taper, sharper shoulder, and shorter neck. These changes increase the case's powder capacity, and increased powder capacity means higher performance with maximum loads.
The .30-30 Ackley Improved is not an extreme example of the type. There is still some body taper, and the neck is suficiently long to easily accomodate 170 grain bullets. Compared to some modern creations, such as the .300 WSM, the .30-30 Ackley Improved looks positively normal, even staid.
Improving a cartridge usually does little harm, but it may also do little good, depending on the shape of the original. Cartridges like the .300 Winchester Magnum, designed with minimum body taper, a sharp shoulder, and a short neck leave little or no room for "improvement." I have never heard of an "improved" .300 Win. Magnum.
The .30-30 is an older cartridge, designed when substantial body taper, a sloping shoulder, and a long neck were commonly employed to assist extraction. In those days, powders were more unpredictable and brass was weaker and less uniform. So the .30-30 is, technically, a case that is amenable to improvement.
P.O. Ackley is probably the most famous wildcatter in history, and he created Improved versions of almost all the standard cartridges of his day. Some time shortly after the end of the Second World War, Ackley got around to the .30-30 Improved.
His blown-out version of the .30-30 has a very sharp shoulder. The case dimensions are .422" base diameter, .405 "shoulder diameter, and .328" neck diameter. Bullet diameter remains .308", case length is 2.04", and overall cartridge length is 2.54".
Ackley claimed that 37.0 grains of IMR 3031 powder behind a 150 grain bullet in his .30-30 Imp. gave a muzzle velocity (MV) of 2617 fps and muzzle energy of 2280 ft. lbs. at permissible pressures. That is, by the way, 5 grains more IMR 3031 powder than I use behind a 150 grain bullet in the standard .30-30 Winchester case.
However, such velocities undoubtedly require a 24" barrel, the same length that is required to get 2400 fps from the standard .30-30 Winchester cartridge. In carbines with 20" barrels, velocities will be substantially lower.
The claimed .30-30 Ackley Improved MV, if correct, is about 200 fps faster than the original with the same weight bullet, and equal to the maximum MV attainable from the larger .307 Winchester case, which operates at a considerably higher maximum average pressure (MAP). The SAAMI MAP for the .30-30 Winchester is 38,000 cup, compared to the .307's MAP of 52,000 cup.
One would think that to equal the MV of the .307 cartridge with the same bullet, the smaller .30-30 Improved must be operating at about the same, or higher, pressure. Or achieving less velocity than claimed. Or something . . ..
In any event, the .30-30 is a fine hunting cartridge and the .30-30 Ackley Improved, with its extra 5 grains of IMR 3031 powder, can only be better. Best of all, reaming the chamber is all that is required to convert a standard .30-30 rifle into a .30-30 Improved.
Copyright 2006, 2013 by Chuck Hawks. All rights reserved.