The Model 70 is considered by many to be the most perfectly designed rifle ever. The Model 70 is a rifle of history and unequalled modern performance — especially with the revolutionary BOSS. U.S. Repeating Arms Co. is excited to offer this incredible new patented technology on the Winchester Model 70. THE BOSS™ AND YOUR MODEL 70. (BALLISTIC OPTIMIZING SHOOTING SYSTEM) These are additional instructions specific to your BOSS™ equipped Model 70 rifle.
vibration. At this optimum point, either at the peak or valley of a vibration wave, the rifle barrel is momentarily motionless. The suggested “sweet spots” (found on a separate sheet supplied with this manual) are the starting points for determining the optimum accuracy of your BOSS equipped Model 70. Once the true “sweet spot” is determined for a given ammunition, your rifle will consistently deliver extraordinarily tight groups.
THE “SWEET SPOT” Precision accuracy is achieved by calibrating your rifle caliber and ammunition with a “sweet spot” setting. The “sweet spots” for your Model 70 are found listed on a separate sheet supplied with this manual. If you are missing the “sweet spot” sheet or if there is no “sweet spot” listing for your rifle caliber or ammunition, call U.S. Repeating Arms Co. at 1-800-945-1392. “Sweet spot” settings were determined through extensive testing by US. Repeating Arms Co.
PRELIMINARY ADJUSTMENTS you will need to calibrate your BOSS. Move the micrometer adjustment ring, on the bottom of the locknut, so that when bottomed out on the threads the “0” is aligned with the vertical hatch mark. To adjust the micrometer adjustment ring, insert your fingernail or a small pointed object in the split of the ring and simply rotate the ring (See Figure 3). Before adjusting your rifle to the “sweet spot,” it is important that your BOSS is calibrated with the barrel.
micro-adjustable locknut is turned either clockwise or counterclockwise until it rests on the desired “sweet spot” number inscribed on your rifle’s barrel. One full revolution of the locknut indicates one full change in setting or one index mark on the barrel. 1/10 turn increments are set by turning the micro-adjustable locknut until the desired setting lines up with the longitudinal hatch mark on the barrel.
EXAMPLE 2 — 1. Suppose you have a 30-06 Sprg. Model 70 with 150 gr. cartridges. Referring to the “sweet spot” chart you will find the average “sweet spot” is 1.8. 2. Adjust your BOSS and rotate the micro-adjustable locknut counterclockwise until the edge of the locknut lines up or rests on the marking for 1 on the barrel. 3. Since the “sweet spot” is listed as 1.8, the 8 inscribed on the micrometer adjustment ring should line up with the hatch mark on the barrel (See Figure 6).
CAUTION: WHEN ADJUSTING THE SWEET SPOT NEVER SET THE BOSS BEYOND THE 10 SETTING ON THE BARREL. With the BOSS set beyond 10, the BOSS could become loose, misaligned or fall off when firing the rifle. This could result in serious injury to yourself or others. MORE PRECISE IMPORTANT: Each time you set the “sweet spot,” the body of the BOSS must be tight against the microadjustable locknut. Failure to keep the components tightly locked will adversely affect accuracy.
We highly recommend that your rifle be cleaned with the BOSS installed on your barrel. Remove the bolt and clean from the breech end. To check for adequate clearance, it is recommended that a piece of paper, folded once, be able to pass between the barrel and stock without any interference. If the barrel is not free-floating, take your rifle to a competent gunsmith or send it to U.S. Repeating Arms Co. Service Center.
3. If absolutely necessary, the BOSS may be removed to facilitate cleaning. Clean the BOSS by removing the locknut and body from the rifle. With the components disassembled, wipe each component with oil. Lightly oil all threads and make sure exhaust holes on the body of the BOSS are free of obstructions. 4. Reassemble your BOSS by screwing on the microadjustable locknut then the BOSS body.
You Are Responsible For Firearms Safety As a gun owner, you accept a set of demanding responsibilities. How seriously you take these responsibilities can mean the difference between life and death. Failure to follow any of these instructions can cause extensive damage to your gun and/or possible serious injury or death to yourself and others. There is no excuse for careless or abusive handling of any firearm. At all times handle any firearm with intense respect for its power and potential danger.
6. BEWARE OF BARREL OBSTRUCTIONS, for the safety of both your gun and yourself. Mud, snow, and an infinite variety of other obstructions may inadvertently lodge in a barrel bore. It takes only one small obstruction to cause dangerously increased pressures that can ruin (swell or rupture) the finest rifle barrels. BEFORE CHECKING FOR A BARREL OBSTRUCTION, BE CERTAIN NO LIVE ROUND IS IN THE CHAMBER AND THAT THE MAGAZINE IS REMOVED AND FEED MECHANISMS ARE COMPLETELY EMPTY.
11. BE SURE OF YOUR TARGET AND BACKSTOP. Particularly during low light periods. Know the range of your ammunition. Never shoot at water or hard object. 12. ALWAYS UNLOAD YOUR RIFLE'S CHAMBER BEFORE CROSSING A FENCE, CLIMBING A TREE, JUMPING A DITCH OR NEGOTIATING OTHER OBSTACLES. Refer to "Unloading The Rifle" for instructions on the unloading of your rifle. Never place your loaded rifle on or against a fence, tree, car or other similar object. 13. WEAR EYE AND EAR PROTECTION WHEN SHOOTING.
20. READ AND HEED ALL WARNINGS in this instruction book, on ammunition boxes and with all accessories that you install on your firearm. It is your responsibility to secure the most up-to-date information on the safe handling procedures of your Browning gun. Browning assumes no liability for incidents which occur when unsafe or improper gun accessories or ammunition combinations are used. 21. PERIODIC MAINTENANCE -- AVOID UNAUTHORIZED SERVICING.
