The .270 Ackley Improved Savage
By Chuck Hawks
Throughout the first half of the 20th Century the Model 99 Savage was one of the best selling rifles in North America. This popular lever action rifle used a rotary magazine that allowed the use of pointed (spitzer) bullets, which gave the Savage rifle a big advantage over the tubular fed Winchester Model 94 and Marlin 336.
While the Model 99 was chambered for popular woods cartridges such as the .30-30, Savage developed high intensity cartridges specifically for the short action of the Model 99. Among the most successful of these, and still well known today, are the .250-3000 (the first factory loaded cartridge to exceed 3000 fps) and the .300 Savage (the forerunner of the .308 Winchester and 7.62mm NATO).
The .300 Savage was designed to equal the muzzle velocity (MV) of early .30-06 loads (2700 fps) using 150 grain bullets in a cartridge short enough to feed through the Model 99's magazine. After the .270 Winchester was introduced and began to attract a following, some Savage 99 owners wanted a .270 caliber cartridge for their favorite rifle. Savage, for whatever reason--probably because the performance of the .270 Winchester simply could not be achieved in a short action case--never developed a .270 for the Model 99. Naturally wildcatters, P.O. Ackley among them, were less reluctant to accept the challenge.
The result was the .270 Ackley Improved Savage, or just .270 Savage. The .270 Savage is essentially the .300 Savage case necked-down to accept .277" diameter bullets. Since the .300 Savage case came with a sharp shoulder and a short neck, there wasn't actually much room for "improvement," although Ackley tried. The key dimensions (rim diameter and thickness, head diameter, case length, and cartridge overall length) are the same as for the .300 Savage.
The advantage of the .270 Savage is that for any given sectional density (SD) a .270 bullet is lighter and has a higher ballistic coefficient (BC) than a similar .30 caliber bullet, allowing higher velocity and a flatter trajectory. With 150 grain bullets the .270 Savage has no particular advantage over the .300 Savage (except superior SD), but with the popular 130 grain bullet the .270 Savage is a nifty cartridge.
Ackley's published ballistics for the .270 Ackley Improved Savage show that a 130 grain bullet in front of 39.0 grains of IMR 4064 powder can achieve a MV of 2763 fps and ME of 2200 ft. lbs. Based on a bullet with a BC of .408, the 200 yard velocity would be 2338 fps and the 200 yard energy 1578 ft. lbs. These are very useful ballistics for all CXP2 game.
Using the Speer 130 grain Hot-Cor spitzer bullet (BC .408) the trajectory of that load looks like this from a scoped rifle: +2.7" at 100 yards, +3" at 125 yards, +1.5" at 200 yards, -1.4" at 250 yards, -6.0" at 300 yards. The maximum point blank range (+/- 3") is 271 yards.
Note that these ballistics are superior to those of the new 6.8mm SPC Remington, which can only achieve similar muzzle velocity by using a 115 grain bullet. The .270 Savage is a pretty good cartridge!
Copyright 2006, 2012 by Chuck Hawks. All rights reserved.