Technical Bulletin

August 12, 1999

Technical Bulletin 2: Nose-Diving AR-10 Followers

Beginning in May 1999, ArmaLite received a number of complaints of poor AR-10 magazine function.  This problem has been traced to shallow magazine catch plunger holes in some followers.

The shallow holes produce excessive compression of the plunger spring.  In extreme cases the plunger cannot fully enter the hole.  The excessive spring energy forces the plunger strongly to the rear, where it presses against the rear of the magazine box.  This forces the follower forward, and it can jam against the front of the magazine box.

To determine if the bolt catch plunger hole is too shallow, press a ¼ inch diameter rod or drill bit into the hole.  The straight sides of the hole must be 1.5 inches deep, plus or minus .05 inch.

The owner can correct the problem by drilling the hole to the proper depth, or by cutting two coils off of the plunger spring.  ArmaLite will inspect and correct all followers returned to the factory.  The complete magazine should not be sent.

The problem can also occur if dirt enters the magazine, or if the follower has burrs that catch in the magazine box.

MAW

© 1998 ArmaLite, Inc.