Another place where there should be plenty of clearance is at the two ends of the rear handguard, at the points marked A on the photograph. If there is pressure at these points when the gun is cool, it will be relieved as the barrel heats, and the change of conditions will change the location of the shots on the target.

Two more points at which a tight fit is detrimental to accuracy are those marked B, where the ends of the upper band guard should be free enough for longitudinal play to be felt easily when it is pushed forward and backward by hand. It should also be quite free over the barrel and operating rod so that there is no chance for the wood to make contact with either of these parts.

The gas cylinder must have quite a snug fit on the barrel at the point C and must leave a clearance at the rear end where the ring fits over the barrel at the forward one of the two points marked B. Any absence of a proper gas seal between the barrel splines and the mating portion of the gas cylinder at point C can be overcome by plating the barrel with hard bronze or nickel. The ring at the rear end of the gas cylinder that surrounds the barrel should have at least .001 inch clearance. It is preferable to have this loose enough so that a strip of thin paper can be passed between this ring and the barrel.

The lower band should be fixed quite firmly to the barrel. Clearance between the lower band and operating rod at point D should be such that there is no binding contact between the band and rod as the rod is driven to the rear.

For best accuracy, the action should be firmly bedded in the stock. A tightly locking trigger guard should draw the rear end of the receiver down to rest firmly on the slightly raised flat portion of the stock at that point.

That portion of the stock inletting designed to accommodate the recoil shoulders of the receiver should provide balanced support and should not permit any lateral movement. Selection of stocks or possibly the use of shims would correct most cases of this nature.

The urgent necessity for the utmost speed in wartime production has sometimes resulted in rear sights having too much play for best target accuracy. Any excess clearance between aperture and rear sight base can be corrected by plating with hard bronze or nickel.

The time required for the hammer to fall is about the same as the lock time in the 1903 Springfield, or about the .0057 second. However, a sharper hammer blow will give faster and more uniform ignition, and will tend to produce smaller groups. The present mainspring can be replaced to give more tension and hence a smarter hammer blow, which will result in faster ignition and lock time, which is conducive to accuracy. It is also an advantage to the shooter to have an extremely short time elapse between trigger pressure and primer indentation. Obviously the disarrangement of aim can be kept to a minimum with faster hammer fall.

The occasional “long trigger pull” may be corrected through the use of a stone in the hands of a trained armorer or gunsmith. Rather than the sear, it is the dressing of the front hammer hooks that removes M1 “creep.”

If a star gauge is available, the point to look for is any slight tightness of the groove diameter right at the muzzle. This may occur in manufacture as the rifling head wears, and is not good for the accuracy. If any such constriction does exist, it will be in the grooves only and can be removed by careful lapping, taking care to enlarge the groove diameter only and not the land diameter.

It is well to check rifles to see that the forward end of the piston rod clears the gas cylinder lock screw by not less than .05 inch. Insufficient power results if the gas must act on the piston from a chamber less than .05 inch deep. This can be checked by placing a single pellet of B-B shot in the gas cylinder to be compressed by the piston as the action is allowed to slam shut. By measuring the flattened pellet the clearance may be determined.

The points mentioned above cover only a few of the steps that may ultimately be taken to make the M1 rifle into a first-class target instrument. I am confident that it is potentially as accurate as any service rifle ever made, and that with the same care that has been bestowed on the 1903 National Match rifles in the past it can be made to give long-range accuracy that will excel that of any other military arm.