As I see groups approaching half
an inch at 100 yards and a few near half- minute out to 300 yards, I see the .30-06 Ackley Improved ascending to near great heights. It also is an attractive cartridge to look at. THEN TO THE STEALTH II
MODEL 70 WINCHESTER … A RIFLE YOU CAN BET ON Earlier in this article I mentioned
This pair of cartridges continues to demonstrate most excellent accuracy and performance for the author. From left: Case fi re-formed from .30-06 Springfield to .30-06 Ackley Improved with 40-degree shoulder; .300 Winchester Short Magnum. These case confi gurations show marked difference in length, head, and body diameter as well as shoulder shape. Though shorter, the Magnum case develops appreciably greater velocity … and recoil … than the .30-06 Improved counterpart.
increase. As mentioned, I’ll show the 150-grain bullet with a few basic velocity comparisons, including the .308 Win- chester, .30-06 Springfield, and .30-06 Ackley Improved. I’ll go directly to the reloading manual top listings of velocity for each cartridge generated by at least a half dozen different powders for each case. They are as follows: 150 gr. .308 Win. / 2,900 fps; 150-gr. .30-06 Springfi eld / 3,000 fps; and 150 gr. .30-06 Ackley Imp. / 3,100 fps. These velocities compared closely to those I chronographed later in the 28-inch barrel. Then, as a varmint cartridge with 110-gr. bullets at 3,500 fps or 125-gr. bullets at 3,350-3,400 fps, things got more interesting. The premium grade Broughton
barrel with its 1:10" twist handled match- grade bullets ranging from 150 gr. through 168 gr. very well. Some half- minute groups out to 300 yards began to get interesting. At the time of this writing, I had just gotten started with some super bullets. Some greats like Sierra’s 168-gr. MatchKing, Lapua’s 167-gr. Scenar, Si- erra’s 155-gr. Palma Match, Hornady’s 168-gr. A-Max, Berger’s 168- and 150-gr. Match, and Nosler’s 155-gr. Match … all kept me at the bench with interest high.
Page 182 October — December 2011
that I would cover, in more detail, a remarkable rifl e and cartridge that has become a pleasant part of my work. As my readers know, I have become a very de- voted switch-barrel rifl eman. I have more than a hundred rifl e barrels of switch- barrel status … each with a history of its own and used on a wide range of actions. There is nothing out of the ordinary
about the rifl e I had made a bet on – that it could be made to deliver half-minute groups chambered to the not-so-mild .300 Winchester Short Magnum cartridge described herein. It began its stint with me as a Model 70 Winchester Stealth II short action, soon converted to a switch barrel rifl e. This rifle came with a .25 Win-
chester Super Short varmint weight barrel and I added a .243 Winchester Super Short cartridge on a Douglas 1:10" twist barrel … and fi nally a Krieger barrel chambered for the .300 Winchester Short Magnum. The original .25 WSSM factory bar-
rel shot quite well, as did the .243 WSSM Douglas barrel that I had added, but my primary immediate interest was directed to the .300 WSM. I had nothing but posi- tive feelings for this project, particularly with the bet on that the .300 WSM-Model 70 combination would deliver half-min- ute of angle or under accuracy … quite an undertaking with a production rifl e in a fairly high-intensity, .30-caliber cartridge. It is known that less than perfect action- to-stock bedding, along with heavy recoil, have an inverse relationship on accuracy. But few of my rifl es had received
more attention to preparation than this Model 70 Winchester. I had installed three bedding pillars in the composite stock, which already had an integral bedding block to begin with. This appeared to be a Bell and Carlson target-style stock closely resembling the confi guration of the older style Winchester Marksman stock. I had installed a Timney trigger ad-
justed down to a pound … a really crisp piece of work. In the mount and sight department,
here, too, precision was top priority. I installed a Near Mfg. Picatinny mount- ing system with two additional 8-40 base screws between the existing two pairs of screws. These were installed using Brownell’s Tactical Screw Conversion Kit. Such a mount system actually adds stiffness to the receiver as a further aid to precision. I mounted a newly intro- duced Sightron scope – Sightron’s SIII 6-24x50mm long-range tactical model. I haven’t seen a scope better adapted to tar- get or varmint use. It comes with a reticle they named the MOA-2. It has a fine centrally positioned dot with fi ne cross lines spaced two minutes-of-angle apart, upward, downward and to each side. In my opinion this beats the mil dot system, which few shooters really understand … at least those I’ve talked with. Optics are bright and clear, enabling me to clearly see backlighted bullet holes at 300 yards. Sightron scope lenses are coated with seven layers throughout the entire scope with their Zact-7 Revcoat™ system. The Sightron tactical scope adjust-
ment knobs are quite large (1.20"), easy to read, audible, and easy to feel. The scope provides 100 MOA elevation adjustment for the very longest-range target or var- mint shooters. The VARMINT HUNTER Magazine® regularly publishes pictures of shooters having shot varmints at ex- treme ranges. The Sightron 6-24x Tactical scope would leave little to the imagination here. It sure makes it easy to extract the most accuracy possible from a rifl e, be it varmint or target model. Having passed each test on my
scope testing unit, I got on with load selec- tion and testing the Model 70 Stealth II in caliber .300 Winchester Short Magnum. I used all the bullets mentioned herein for the .30-06 Improved … plus a few others. So was the rifl e ready to shoot? Well … I made book on it. Following a few days of preparation, the rifl e was ready to test. With one very serious and observant wit- ness close by watching things, I got on with the shooting. I began with a load using Sierra’s
168-gr. MatchKing bullets. The fi rst fi ve shots showed but a ragged hole, so I didn’t move the rifl e as I stayed with this group for 10 shots. It was a Wow! The 10 shots went into an amazing 0.375-inch. There were three groups in the 0.2s, and but a single group just over half an inch at 0.504 inch. Word got out about this .300 Winchester Short Magnum sleeper. No
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