Tech Note

August 28, 2001

TECHNICAL NOTE 46: ERRATA SHEET FOR ARMALITE AR-180B RIFLES

PURPOSE: 
This errata sheet provides information that isn't contained in the AR-180B Instruction Manual, or highlights information that is extremely important.  It is part of the AR-180B manual and must be kept with it.

SAFETY:  
Read and understand the safety warnings in the operators manual before you do anything else.  Use good hearing protection, because the recoil check (muzzle brake) concentrates muzzle blast near the shooter.

ZEROING THE FRONT SIGHT FOR WINDAGE:   
The AR-180B’s screw-clamping front sight base allows the owner to zero the front sight for windage, much like the front sight of the M-1 rifle was zeroed.  This results in the rear sight being nicely centered in the rear sight base of the zeroed rifle.

To do so, center the rear sight in the middle of the rear sight base.  Fire a three-shot group.   To adjust the next shot group to the left, loosen the clamping screws and shift the front sight to the right very slightly.   To shift the group to the right, shift the sight to the left.  Make final adjustments by zeroing in the normal manner using the windage knob of the rear sight.  Elevation is adjusted by raising or lowering the front sight.  

VISIBLE MAGAZINE CATCH SPRING:              
Like the aluminum-framed AR-10 and M-15 rifles, the thin web of material between the magazine well and the magazine catch spring pocket may produce an opening in the middle of the rear wall of the magazine well.  This is a normal condition with no effect on function.

BREAK-IN PERIOD: 
ArmaLite rifles are made more tightly than other rifles of similar design.  A break-in period of 200 rounds allows machined or phosphate-coated surfaces to mate.

MARK A. WESTROM
President