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Letter Re: Comments on FAL Rifle Gas Regulation
Mr. Rawles:
These sage comments on FN
FAL gas adjustment from my friend and colleague,
John Krupa, Director of Training for DSA [an
American maker of FN FAL clone rifles. The following is re-posted with the
permission of DSA]:
"Not knowing that one can control gas-flow on this weapon has led to countless
customer-service calls to DSA, complaining that the rifle 'doesn't work.' The
following is laid out in great detail in the Owners's Manual, of course, but
we
are happy to explain to each owner how the gas-regulator works and then walk
them
through correct gas-regulator adjustment. Invariably, when we're finished, like
a miracle, the rifle suddenly runs fine!
(1) The gas vent is directly behind the base of the front sight. We start the
process with the gas-regulator set to the full-open position, which is # 7
on the gas-regulator dial. The vent-hole will be visibly open all the way.
Next, we start to close off the gas-regulator vent by turning the dial
clockwise two clicks, which will place it at # 6. You will now see
that the vent hole is partially occluded. From here, we can start our live-fire,
function testing.
(2) Charge a magazine with a single round of ammunition. Insert the magazine
into the rifle and chamber the round. Holding the rifle in a normal, standing
position (bench-resting is not recommended) aim into the impact area and fire
one round. When the bolt fails to lock back, [we can conclude that] not enough
gas is driving the piston into the bolt group for a complete cycle of operation.
So,
close the gas regulator another, single click, which will put it at 5 1/2,
and then repeat the one-shot drill. Continue to close off the gas-regulator,
a click at a time, until consistent (three in a row) bolt-lock is achieved
(3) When the bolt thus consistently locks to the rear after firing a single
round, insert a magazine charged with five rounds, load the rifle, and fire
all five in rapid succession. Once again, the bolt needs to unfailingly lock
to the rear as the last round is fired.
(4) Once your rifle passes the 'five-round test,' close the gas-regulator two
more clicks! The gas regulator is now 'set.' Just about all rifles
we issue for student use have a final set at 4 to 4 . That is pretty standard.
(5) When the rifle gets hot, dry, and dirty, and starts short-cycling, you
can use the gas-regulator dial to quickly make incremental increases in
gas
pressure, instantly restoring the rifle to normal functioning.
I don't recommend closing the gas-regulator completely, as you suggested
in your last Quip, unless absolutely necessary. What concerns me is not excessive
wear-and-tear on the rifle. The DSA/FAL is a robust, military rifle that is
designed for heavy use in hostile environments. It will take whatever you can
give it! Nor is my concern with accuracy. Practical accuracy is unaffected
by gas-regulator adjustments. Nor is my concern with recoil attenuation. Soft
recoil is nice, but we can all handle recoil. The real problem is with case-extraction
that is so violent it may result in cases being literally pulled apart as the
bolt moves to the rear. The front half of the case may thus be left in the
chamber, resulting in a stoppage that cannot be corrected
in the short term.
With regard to ammunition:
Ammunition quality is all over the map! Ammunition from dubious sources, reloads
for example, typically exhibit inconsistent head-space and inconsistent pressure.
DSA, of course, recommends against the use of such poor-quality ammunition,
except in exigent circumstances."
Comment: John Krupa is the resident expert, and I will surely
defer to his judgment on this issue, and my advice to FAL owners is that they
adhere to his,
foregoing instructions. The thorny issue is, of course, "exigent circumstances!" When
I have my FAL, some magazines, and a supply of ammunition about which I know
little,
and I've been invited to participate in a fight that is starting immediately,
best bet is to begin with a rifle whose gas-regulator is closed off. I'll put
up with recoil, and I'll take my chances with case-separation, just as long
as
I can be assured my rifle will complete each cycle of operation. Conversely,
when I know what ammunition I'm going to feed it, and I have time to go through
the foregoing gas-regulator adjustment routine, and a range where I can do
the mandatory live-fire, I will surely tune my weapon to maximum advantage.
No contestation there.
Of all dubious ammunition, the most suspect is reloads. Cases that have been
reloaded multiple times are stretched, weakened, and thin in spots. They are
the ones most prone to case-separation, described above, and inspection may
not be helpful. From the outside, one can seldom tell if a case wall is dangerously
thin. "Once-fired-reloads" is a commonly-used platitude, but how
can anyone really know how many times a particular case has been reloaded?
Reloads are thus not recommended for use in any autoloading rifle. - John
