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#Post#: 27--------------------------------------------------
Ammunition Sensitivity
DIR By: allmanav
Date: January 11, 2019, 2:37 am
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[b]Few things are as discouraging to shooting enthusiasts ready
for a good day at the range as having a gun repeatedly jammed up
with failures to feed or eject when using the ammunition on
hand. If the gun is in good working order and there's nothing
obviously wrong with the ammunition itself, you may be dealing
with a case of ammunition sensitivity. Although every type of
firearm can suffer from some form of ammunition-related issue, a
discussion of semi-automatic platforms is a good way to cover
most of them.
Folks who are new to shooting or unfamiliar with ammunition
issues often ask why they are running into problems with
products that have a solid reputation for reliability. Trying to
lump ammunition into "good" and "bad" categories just won't cut
it. Instead, it’s more useful to say that sometimes the shoe
just doesn't fit.
Think about your foot for a moment. It sports exactly the same
set of features as millions of feet around the world (toes,
ball, arch, heel) but at the same time it has dimensions that
make it both subtly and distinctively unique (nail thickness,
toe shape, width, overall length). Once you know your shoe size,
you can move up and down the price scale (from cheap to
expensive) or sideways across shoe brands (Adidas, Fila,
Converse, Nike, etc.) until you find a shoe that fits your foot
and your budget comfortably.
Guns aren't much different when it comes to pairing them with
reliable ammunition. Each individual gun has minute dimensional
differences when compared to the same models that came off the
same assembly line, let alone the much more distinctive
differences that show up when making comparisons across makes,
models and brands.
It's not always a matter of price point but of proper
gun-to-cartridge fit. As you move up and down the ammunition
price scale, and sideways across ammunition brands, you'll find
loads that fit (run reliably) and those that don't. The only way
to know which loads will work for sure is to "try them on" by
firing them at the shooting range. You'll find a variety of
inexpensive loads that run all day long without a hitch, and
premium loads that will too. But like shoes, not every single
option on the shelf is going to be a good fit.
Here are a few of the most common ammunition fit issues that
tend to crop up:
Bullet Shape
Within any given caliber option you'll often find several
different bullet weights and styles including lead round nose,
flat nose, ballistic tips and jacketed hollow points, just to
name a few. Depending on the depth and angle of the pistol's
feed ramp or magazine follower, the tip of the bullet may catch
at the chamber mouth resulting in a failure to feed.
Cartridge Case Material
Cartridge casings are often referred to as "brass" because that
has been a common case material for quite some time. However,
cartridge cases can be made of brass, steel, aluminum or mixed
materials. The Shell Shock Technologies NAS3 9 mm case consists
of an aluminum head, stainless steel cylinder and a nickel
coating. Some companies are even developing polymer cases.
Within a particular category you'll see different treatments of
the metal, like the 7.62x54 mm R rifle cartridges shown here,
with steel cases featuring copper-washed, polymer-coated,
lacquered and zinc-plated finishes.
When a cartridge is fired, the relatively soft cartridge case is
subjected to intense levels of heat and pressure, which
temporarily cause it to stretch and expand before snapping back
into something close to its original size and shape. In some
instances, depending on the gun's chamber and the cartridge case
material, the case's shape is altered just enough to cause it to
stick in the chamber so it does not eject properly.
Some empty cases will pop out when the bolt is cycled a couple
of times, while others will have to be tapped out with a
cleaning rod and hammer. And there's no way to know for certain
beforehand which case materials are going to be reliable. I've
shot guns where brass-case loads cycled smoothly while
steel-case rounds tended to be sticky. However, when I tested a
Mosin-Nagant M44 a while back, the gun was perfectly happy when
stoked with steel-cased ammo, but brass cases were the problem
children of the test.
Low Pressure Levels
Semi-automatic firearms rely on the pressure generated by
cartridge ignition to cycle the action. Due to design
differences, including slide or bolt mass and spring-tension
levels, some semi-automatics require more cartridge pressure to
cycle successfully than others. If a given cartridge does not
generate enough pressure to completely cycle the action of a
particular gun, then malfunctions will occur including stove
pipes (partial case ejection) and failures to feed. The most
dangerous result of low pressure is a squib load (named after
the strange sound they make) which results in the bullet
becoming lodged in the barrel. Pay attention to each shot and
make sure a hole appears in the target down range. If not, stop
shooting, break down the pistol and inspect the bore before
continuing to shoot.
Minute Differences in Cartridge Dimensions
Even though ammunition manufacturers work to meet clearly
defined cartridge dimensions, there are always minute
differences in the finished cartridges that just can't be
detected with the naked eye. This is not only true across
brands, but within batches of ammunition made on the same
machines during the same shift. With low quality ammunition
these variations show up in the form of poor accuracy, reduced
reliability and variations in pressure levels. With good and
high quality ammunition, the variations are so minute that they
go undetected for hundreds, even thousands of rounds.
However, dimensional differences can cause a gun to run poorly
with a certain load or even an entire brand. Case in point: My
brother and I each own the same discontinued model of Smith &
Wesson semi-automatic .22 LR pistol. His has an aluminum frame
while mine is stainless steel, otherwise they are the same gun.
My pistol hums right along with Federal bulk-box loads while his
pistol is a fan of Winchester Wildcats. We switched up these
loads during a family plinking session one time and both guns
immediately began to jam up. Trading out magazines didn't help.
When we went back to our own loads, they both ran smoothly
again. There is nothing wrong with the guns or the ammunition,
they are just not a good fit for each other.
If one or more of the aforementioned issues are the reason your
gun and a particular load of ammunition just won’t function
reliably, there is one simple solution: Stop using that
ammunition and buy something else.
That being said, folks can run into failures to feed or eject
that are not ammunition related. Here are a few additional
troubleshooting steps to consider if your gun is being a finicky
eater:
Clean, Inspect and Lubricate
I almost always start here when diagnosing a gun issue because
the process of stripping, cleaning, inspecting and lubricating a
gun is easy, inexpensive and, more often than not, the solution
to the problem. This is especially true if the gun was running
smoothly with a particular load and then "suddenly" started to
exhibit issues. All too often those failures show up when the
gun is dirty, gummed up with waxy rimfire debris or the
lubricant has been burned off.
Break-In Period for New Guns
Although it's not as common as it used to be, there are still
some factory-fresh guns that need to be broken in at the range
before they can be counted on to run reliably. A tightly fitted
all-steel pistol, like a competition-grade 1911, might need to
be fired between 50 to 200 times to complete the final smoothing
and settling of the moving parts. If the pistol has more than
200 rounds through it then the problem rests elsewhere.
Inspect Magazines and Magazine Springs
Whether a magazine is fixed or removable, tubular or box shaped,
a weak spring can cause failures to feed. Replacing or upgrading
the springs may solve the problem. If a magazine's feed lips are
bent or damaged, that will cause hang-ups as well. If cheap,
no-name magazines or well-made aftermarket magazines do not feed
as reliably in your gun as factory magazines, you'll just have
to bite the bullet and pay more.
Check Your Technique
While shooting technique can affect accuracy and comfort levels
(recoil management) it can also affect reliable operation with
semi-automatic pistols. Not holding the pistol firmly enough
during recoil, which is also known as "limp wristing," can cause
the pistol to malfunction. So, try firming up your hold on the
gun and see if that helps.
Seek out Professional Assistance
Remember that safety is of the utmost importance any time a gun
starts malfunctioning. If it is persistently misbehaving during
a range session and you're just not sure what is going on, stop
shooting the gun immediately. Unload it completely, case it up
and do not fire it again until you call on a professional for
assistance. This could mean calling the manufacturer and
returning it to the factory for repairs, or paying a visit to
your friendly neighborhood gunsmith. You might have a lemon on
your hands, or it may be that the gun needs a simple repair.
Either way, it's alw[/b]ays better to address the problem
directly and safely rather than taking any chances.
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