and just how this rifl e came to be. The .300 Winchester Short Magnum
is a very lively cartridge, not far behind its predecessor, the .300 Winchester Mag- num. I could see within its walls a case capable of extreme accuracy. Designed by Winchester in 2001, this case, shorter by 0.520" than the .300 Winchester Mag- num, was developed to extract the most performance attainable from a .30 caliber round chambered in a short action rifl e. The Short Magnum is not a belted case as is its counterpart the .300 Winchester Magnum. Both measure close to 0.535" at the rim, but utilize the same size bolt face. The case type is termed a Rebated Bottle- neck as opposed to a Belted Bottleneck for the .300 WM. The .300 WSM measures 0.5381" at
shoulder diameter, compared with 0.491" for the .300 WM. The base comparisons are 0.5550" for the .300 WSM and 0.513" for the .300 WM. As I fi lled each case to the base of the neck with 760 ball powder, the .300 WSM held 72.5 grains compared to 82.5 grains for the .300 WM. However, they performed quite similarly. The various reloading manuals
credit the .300 Winchester Magnum, us- ing 150-grain bullets with similar barrel lengths, with a 100 fps average veloc- ity increase. This velocity difference, of course, would depend on several factors applicable to each cartridge. However, having loaded both of these cartridges with several makes and weights of bul- lets along with different powders, I found velocities were indeed quite close. In working with two rifl es chambered for the .300 WSM and perhaps seven in .300 WM, I have to give the accuracy edge to the .300 Winchester Short Magnum. I believe this is largely because of case design. I’ll cover this in greater detail as I discuss the rifl es chambered for these cartridges. But fi rst, let’s look at still another .30 caliber car- tridge quite new to me in recent months. ENTER THE .30-06 ACKLEY IMPROVED You’ll not fi nd this cartridge listed
in many of the handloading manuals. It’s my fi rst experience with it and I like what I am seeing thus far. Anyway, as an old wildcatter, I thought I’d give the round a try. I had a well-proven Broughton
28-inch barrel, chambered for the .308 Winchester on a 700 Remington stainless short action converted to single-shot, producing exemplary accuracy with a number of good bullets. The 700 Reming-
As described in text, these are the rifl es used in testing and shooting the two .30-caliber cartridges. Top: Model 70 Winchester Stealth II caliber .300 WSM short action rifl e with Sightron’s new SIII 6-24x50 Long Range MOA-2 tactical rifl escope. Mount used is a NEAR Mfg. base with new Trijicon Picatinny rings. The rifl e wears a Krieger 1:10" twist 27-inch barrel. Below: Model 700 Short Action Remington Stainless in caliber .30-06 Ackley Improved. Rifl e wears a 6-24x42 Sightron scope with Talley bases and rings. This rifl e has a 28-inch Broughton barrel with 1:10" twist 5C rifl ing. The rifl e is pillar bedded into a Bell & Carlson light varmint style stock.
ton action was pillar bedded into a Bell & Carlson stock with the barrel free fl oating. I mounted a Sightron 6-24x42 scope on the rifl e with a Talley stainless steel mounting system. The scope, mount, and stainless action were a neat match. This rifl e has two bolts and also is chambered to two other barrels – one a .221 Remington Fireball. This is a very versatile varmint/ target rifl e. I converted the .308 chamber to
.30-06 Ackley Improved with the Ackley 40-degree shoulder, using one of Dave Manson’s reamers. I learned that because of differences in shoulder confi guration, simply reaming out a .30-06 chamber to the 40-degree shoulder Improved version doesn’t work out. The barrel must be set back. This was another good reason for my using the well-proved barrel, chambered for the .308 Winchester. I also would have knowledge of the best bullets to use as starting loads for the new .30-06 Ackley Improved. I used Lapua cases for the con-
version, which are of match grade and annealed. These cases show as little vari- ance in volumetric capacity and neck wall thickness as any I have used in any of their cartridges. I used Redding dies.
Among their vast reloading die availabil- ity, Redding just happened to stock the .30-06 Ackley Improved with 40-degree shoulder and it wasn’t long before they were at my reloading bench. Aside from Parker O. Ackley’s
Handbook For Shooters and Reloaders, Sierra’s 5th Edition Reloader’s Manual provided the only load coverage for this not-too-popular cartridge, at least in my reloading library. It also is listed in the Third Edition of Handloaders Manual Of Cartridge Conversions, provided by Lutto & Associates, Inc. (Phone 804-346-4309). The Ackley Improved version of
the .30-06 has essentially a straight taper from its 0.470" diameter base to its 0.454" shoulder diameter. This increases shoul- der diameter by 0.013" over the unaltered .30-06 Springfi eld. While Sierra painted a less rosy
picture of the .30-06 Improved, I tend to see this cartridge in a bit different light. My tests showed a fi red .30-06 case holds 70.8 grains of WW 760 powder, whereas the Improved version holds 74.8 grains of the same powder. (Caution: This was a volume comparison and not a suggested charge for this case.) This translates to about 4 percent
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