View Full Version : Technical: Latch, Locking Body how-to

October 06, 2000, 04:04
how can it be corrected? thx

[ August 08, 2001: Message edited by: gary.jeter ]

[ August 12, 2001: Message edited by: EMDII ]

October 06, 2000, 05:23

fix by:

(Revised 09-23-00)

The upper and lower receivers on the FAL are hinged to facilitate cleaning. The two halves snap shut and lock. A lever (lever, locking catch assembly) on the left side of the receiver unlocks the upper receiver by disengaging the catch (catch, locking body). A poor fit of this part results in the receiver snapping open unexpectedly or a wiggle between the upper and lower. The catch is self-adjusting so it can compensate for wear. It is normal and desirable for the lever to to be slightly to the rear of straight up. As the engagement surfaces wear, the lever moves forward. When the lever has moved to the point where it has contacted the rear of the receiver plate, a loose, sloppy fit between upper and lower will soon follow. There are three types of levers: a long upright lever, a short upright lever, and a lever that points forward. There are several cosmetic variations of each type, depending on whether the part is a stamping, one-piece machined, or two parts welded together. The long upright lever is standard. Airborne forces discovered that a parachute harness could activate this lever. Additionally, the inertia of launching rifle-grenades could jar the lever rearward. So FN shortened it, which increased the amount of force needed to move it. Another solution common on paratrooper FALs and most Israeli and South African FALs is a small lever pointing forward. I originally thought this was more desirable, because it's less common, cool looking, and out of the way (or so I thought). After taking a three-day Urban Carbine Instructor's Course with a SAR-48 Para, I decided against this configuration. It is too close to the selector lever and after snapping the safety on and off a few thousand times, I ended up with a blistered, bloody gash on the inside of my left thumb where the edge of this part rubbed.

Often a new receiver combined with a new catch will cause the weapon to snap open. You fix this by modifying the catch. Follow the rule of "cut on the least expensive part" and leave the tab on the receiver alone. Properly adjusted, the lever should point about 5 degrees to the rear. As the parts wear (years of heavy use), it will move into the vertical position.

First remove the stock assembly. There is a screw in the rear (screw, retaining, locking catch body). Removing this frees the cross-pin (pin, retaining, locking catch). Be careful as this pin retains a spring and plunger that are under tension (stay, locking catch spring). You can now remove the lever and the catch. Apply Dykem or marker pen on the engagement surface and reassemble. Work the upper receiver open and closed several times. Disassemble and hone or sand the high point where the Dykem was rubbed away. Repeat this procedure until the latch positively locks. Test by inverting the rifle and tapping the end of the barrel on your bench. The receiver must not pop open.

T. Mark "Gunplumber" Graham
Arizona Response Systems
5501 North 7th Avenue, Phoenix, AZ 85013
623-873-1410 http://www.arizonaresponsesystems.com

October 06, 2000, 05:32
thx gunplumber........great post for a fix! i will try this.------the slash man!

October 06, 2000, 05:34
the latch is long---stg-58 by enterprise....it is fully forward----no degree of angle.

October 06, 2000, 05:39
the movement is lateral......not vertical.....does that make a difference?

October 06, 2000, 12:13
With the rifle broken open, is there a lot of play in the hinge? Could be an issue with the hinge, not the latch. Could be a worn hinge pin or oversized holes in lower rcvr hinge. I guess it could be a worn upper receiver hole, but I think this is unlikely.


August 07, 2001, 23:29
And don't forget PMDK!
(Magic Marker - "poor man's Dye-Kem")

moved to FAQ

August 09, 2001, 19:12
Obviously, make sure it is checked with the receiver cover off. An improperly fitting(long)cover will not allow the latch and lever to seat where they should.