Precision Bedding For Winchester Model 70 Stealth II Rifles

As I bed the action of a rifle, I liken it to going quietly to sleep— the less tossing and turning, the better. The metal-to-stock contact must be as uniform and solid as possible. An action that moves around and fails to settle down in its bed won’t allow its groups to settle down very well either. I’ve termed these "restless groups." Here I will cover precision bedding a Winchester Model 70 short action; a bolt action Stealth II Varmint rifle into its factory-issue composite target stock.

In addition to the original .25 Winchester Super Short Magnum, I have chambered this rifle for the .243 WSSM and .300 Winchester Short Magnum, conforming to my own switch barrel rifle process. Not all rifle action types are suited to deliver top-notch accuracy without some help. This is particularly true of a high percentage of bolt actions with magazine cutout resulting in measurably weaker receiver side rails.

Included here I have placed the Winchester Model 70 receiver, which isn’t exactly on top of the bench-rest accuracy short list. Some of these rifles shoot enviably well, but as a rule, considerable coaxing is in the cards. I have experience with scores of bolt action rifles, including several dozen Model 70 Winchesters, in a variety of barrel weights and calibers, both pre-1964 and later.

I made the statement that I believed I could get this short-action Model 70 Winchester rifle chambered for .300 WSM, to regularly deliver half-minute-of-angle or smaller groups with well thought-out handloads. As I removed the action and stripped it down, it paled in comparison to other actions I have become used to extracting extreme accuracy from. It felt so light in my hands.

I was surprised to learn the Model 70 Stealth II has a 28 thread-per-inch receiver thread pitch as compared to the more common 16 or 20 thread pitch, as used on most other rifle receivers, including other M70 Winchester, Remington 700/40X, et al. The faster 1:28 thread pitch can have bearing on barrel shoulder axial preload, if excessive torque is applied.

My other concern was in bedding the short action Model 70 with its open magazine to a sufficiently-rigid receiver that could withstand suspension of a 27-inch target-weight rifle barrel. Considerable attention would have to be devoted to the action bedding to accomplish this, as I will cover in some detail as I move along. Top, receiver with action screws (central screw added by author). Below, one piece trigger guard and floor plate assembly.

Center, top view of stock where selective precision bedding will take place at recoil lug—later central bedding—and rear tang area. Below, underside view of M70 Stealth II short action showing bedding contact surfaces.

The rifle came into my hands chambered for the .25 WSSM set into its factory-provided, target/varminttype, composite stock, which was made by Bell and Carlson (Belland- Carlson.com, These stocks have an aluminum bedding The new action screw would later mate with the otherwise unused screw hole in receiver. Floor block cast into the stock with rails projecting out into the forend and back to the pistol grip area of the stock.

The original .25 WSSM cartridge, as received on this action, produced quite good accuracy for a production barrel, at well under plate latch is seen at right.

For the new chambering in .300 WSM I went with a Krieger 1:10 twist, number 8 contour, 416 stainless barrel finished at a 27" length (KriegerBarrels.com, I chose to use a removable pilot reamer from Dave Manson Precision Reamers with a 0.2995 bushing and a standard SAA- MI throat. (MansonReamers.com, Grand Blanc, MI 48439, I’ve come to trust the performance of these precision reamers. I replaced the factory Model 70 trigger with a Model 401 Timney trigger.

The flat forward support arm of this trigger served as part of the very solid, central bedding support as the pictures will show (Timney- Triggers.com, The Model 70 action is quite unlike the typical cylindrical style receivers, which hasn’t really changed that much over the years since its minute-ofangle range with several bullets. birth in 1936.

There was a revised version of the Model 70 in 1964 involving several stamped-out parts and a push-feed cartridge feed system replacing the old Mauserstyle claw extractor, along with a few other

Here the forward tang on the Timney trigger would replace the sear on the Model 70 trigger and serve as a solid action support. things at that time. The Stealth II has a short action with a one-piece aluminum trigger guard hinged floor plate assembly spanning 7 1/4 inches from the front recoil lug screw to the rear tang. Distance between screw holes in 6 3/8 inches. Two additional Steel Bed pillars are positioned at the sides of the central screw hole, forming a most solid triangular central pillar bed.

Note addition of brass pillars at rear tang and forward action screw hole. This top view shows precisely where pillars mate with critical action surfaces. The one piece scope base, along with a precision set of scope rings, also add measurable rigidity to a well-bedded action. Receiver Bed The Model 70 Winchester rifle has a full square inch of contact surface behind the recoil lug with the front action screw at center. If well bedded, this contact surface alone provides very solid front support.

From there I directed my attention to the rear tang surfaces. Again I added a fulllength brass pillar at the meager surface in the rear tang area. This was surrounded by the integral aluminum bedding block, providing a full square centimeter of bedding surface here alone. I also added bedding surface covered with Steel Bed from Brownells behind the tang and at the laterally positioned surfaces just forward of the screw hole.

These rear tang surfaces provided a very solid support of more than three square centimeters. I then studied the bedding located above and surrounding the central trigger guard screw, which has been a thorn in the side of many Winchester Model 70 riflemen.

Having worked with this action for more than 60 years, I learned early on that its center screw can cause all manner of consternation attributable to I still added a fulllength, centrally positioned, brass pillar downward from the flat surface surrounding the front guard screw to the bottom adjoining the front, lower end of the action screw. This is a 1/4-28 thread, capable of much draw-down torque. action movement and springing.

For some time I just let the central action screw float loosely, just sufficient to hold the trigger guard in place. But before attempting to make a solid bed beneath the central action screw, the bedding fore-andaft at the recoil lug and rear tang must

300 WSM Model 70 Winchester Stealth II precision-bedded action. A Krieger 1 in 10 twist barrel was used in this switch barrel rifle chambered with a reamer from Dave Manson Precision Reamers. The upper left groups were shot with 155 grain Sierra Palma bullets. The quarter-inch group at right center was shot with 168 grain Sierra bullets. Three lower groups were shot with 168 grain Berger bullets.

We couldn’t even dream of performance such as this without a perfectly bedded action, a most vital link in the accuracy chain. be as solid and as well aligned as possible. A careful analysis shows there are two laterally opposing wings surrounding the central screw hole in the action. Immediately downward from this position in the aluminum bedding block there are surfaces for two added pillars.

Additionally there is room immediately to the rear of the central screw hole for still another bedding pillar of at least a square centimeter resting on the aluminum bedding block. As a sort of fortuitous finding, I used the solid, flat extended portion of the Timney trigger as support to the American Gunsmith Mailing List Policy Like many other publishers, we make portions of our customer list available to carefully screened companies that offer products and services we believe you may enjoy.

If you do not wish to receive these offers, and/or information, please let us know by contacting us at: American Gunsmith Opt-Out Program Norwalk, CT 06854 Please include your current mailing label. underside of the action. The thin space between these two surfaces is carefully measured for thickness and a flat, metal surface plate is interfaced between these parts and bonded in. I used Steel Bed material to microscopically fill the gap between these metal surfaces.

At this stage a 1/4-28 countersunk socket head screw was fitted just forward of the hinged magazine cover latch on the floor plate trigger guard assembly, which also is supported by pillars. As a test for fit, torque is later applied to the center screw as the tang screw and recoil lug screw are snugly in place. This maneuver incidentally will reveal even the smallest amount of action-to-stock movement in a rifle. Further tests allude to action rigidity and springing, covered in a separate article.

No stones remained unturned on my journey for half-minute-orunder accuracy from a production rifle chambered for a cartridge as potent as the .300 WSM. As the groups were being observed, few rifles I have worked with in larger caliber have fared any better. For example, one 100-yard, 10-shot group using 168 grain Sierra Match King bullets went into a very respectable 0.375-inch group. Eleven groups using both Sierra and Berger bullets averaged in the 0.3s.

There were three groups in the 0.2s and only one group just over a half inch at 0.504 inch. This doesn’t even take into account the many fine bullets and components that later will be tested in this rifle. Adam Braverman at Nammo Talley (Nammo. com, sent me some worthy looking Lapua 155 and 167 grain bullets that fared very well in early tests. One other bullet I must mention is Berger’s 135 grain, flat base, match bullet.

With 65 grains of Accurate 4350 and Nosler cases, it’s showing me several groups around a quarter-inch. Converting a production rifle to custom rifle performance demands a good deal of well thought-out planning, limited only to our resources and creativity. AG