Technical Bulletin

September 8, 1999

Technical Bulletin 4: Recall of Lot C Bolts

Purpose: To replace all bolts from lot “C”.

ArmaLite has been advised of five AR-10 bolts that have broken in use.  This is a matter of great concern at ArmaLite: until this lot NO AR-10 Bolt has ever failed.

Analysis of the bolts finds that a sharp edge on the cam pin hole allows the formation of stress fractures that cause the bolt to break through the hole.   In one case, improper heat treat of the steel combined with use of the “hottest” load on the commercial market caused the locking lugs on either side of the extractor to break.  There have been no injuries caused by the breaks, but adjoining rifle parts have received surface damage.

We consider this issue severe, and are therefore replacing all bolts from lot C. They are identified by a letter C stamped on the body of the bolt, just to the rear of the bolt lugs.  The letter should be visible by merely removing the carrier assembly from the upper receiver and reading the lot letter on the bolt.     The letter is small, so it's important to use a magnifier to make sure that what looks like a C at first isn't actually a D or G.  If no lot letter is present, then the bolt was from a previous lot that used no letter.

The bolts in question are from a lot of 250, and were shipped after September 30, 1998.

ArmaLite will replace all defective lot C bolts upon return.   While at the plant, the customer’s extractor springs and plugs will be replaced at no charge. 

Only the bolt need be returned: it will be replaced with a dimensionally matched and tested bolt, and a check for $7.00 will be returned with the bolt(s)  to cover the cost of UPS shipping and a “bubble pack” shipping packet.  

This letter will be forwarded to all owners of record, to all dealers who received shipments after lot C bolts were received, and will be posted to the Internet and other prominent sites.  We appreciate your attention and help in resolving this issue.

MAW

© 1998 ArmaLite, Inc.