Workbook

6. Insure the rear part of the dust cover channel is not dented. If so, recut with a thin cutoff wheel.

Otherwise, the receiver will shave metal off the dust cover during installation.

RECOIL SPRING TUBE

This is the culprit in many opening and closing malfunctions. They sometimes have small ripples in them –

not quite a bend, but enough to raise a slight ring – similar to a bulged barrel – which can slow the spring

from smooth operation. Take a rod (a section of shotgun cleaning rod is ideal) and slit the end of it. Wrap a

piece of sandpaper around the end of the rod (secured in the slit), lubricate, and chuck into a power drill.

Run in and out a few times. Then take a 45 cal brass or stainless cleaning brush, wrap steel wool around it,

and run this through a few times with lubricant. This should get you a mirror finish. Occasionally the hole in

a wood stock for the recoil spring tube will have warped slightly. This will make the stock hard to install and

can put a slight bend in the tube, detracting from smooth function. Carefully ream this hole, if applicable.

Another common problem with the recoil spring tube is that it may unscrew from the lower receiver. This is

bad. There is a relief cut at the 6'oclock position. It may look like it belongs at 12'oclock, but it doesn't. It is

to clear the bottom of the rat tail when the bolt carrier is in the rearmost position. If it comes out, degrease

and use red thread-locker to secure. There is no reason to remove this other than to replace it, and if needed,

300+ degree F. heat will loosen it. If you don't have it secured tightly, attempting to unscrew the cap on the

end of the recoil spring tube may instead unscrew the tube from the receiver. If the cap is tight, first heat to

melt any hardened grease.

Polish the sides of the plunger on the end of the recoil springs. Don't remove it from the springs. Also, clean

the heck out of the springs. Sometimes on sluggish closing guns or guns that open with too much force, you

simply need to replace these springs.

DUST COVER

Any dents will bind on the top of the bolt carrier and retard both opening and closing. Dents can be gently

removed by tapping from the inside with the dust cover supported on an anvil. Sand until smooth.

Significantly bent dust covers are best replaced.

RAT TAIL AND HAMMER

The rat tail of the bolt carrier is occasionally bent by attempting to slam the upper and lower receiver closed

with the bolt carrier not in the forward position and properly aligned. This bend can cause binding inside the

recoil spring tube, giving sluggish operation. Carefully straighten the rat tail if necessary. The hammer has a

clearance cut to bypass the rat tail and strike the firing pin. Insure this is enough clearance. Some US made

hammers (Hesse in particular) are either warped during heat treat or the pivot hole drilled slightly off center,

which results in the hammer striking the rat tail just before striking the firing pin, resulting in light primer

strikes and misfires. Assembling the rifle without the dust cover will make any areas which need to be filed

and sanded easily apparent.

CHAMBER

Sometimes there are burrs in the chamber, or deposits of hardened grease. Insure it is clean. A good

indication something is wrong is if an unusually small locking shoulder would be required. These deposits

may be on the shoulder of the chamber, which is usually in shadow in all but the brightest direct light and can

be hard to see. On even rarer occasion, the chamber is simply out of alignment or the throat not deep enough

to handle the wide range of tolerances found on surplus ammo. Although the typical FAL or L1A1 barrel is

chrome lined and cannot really be recut without compromising the chrome lining, chasing the chamber with a

finishing reamer may shave any minor imperfections without cutting all the way through the chrome. It will

definitely remove any foreign matter.

GAS BLOCK, GAS TUBE