The Gun Digest Book of the AR-15, Volume 4

362 Pages·2012·15.65 MB·English

by  Patrick Sweeney

Gun Digest®
Book of
THE AR-15

Volume 4
PATRICK SWEENEY
Thank you for purchasing this Gun Digest eBook.
Sign up for our newsletter and receive special offers, access to free content, and
information on the latest new releases and must-have firearms resources! Plus,
receive a coupon code to use on your first purchase from GunDigestStore.com
for signing up.
or visit us online to sign up at
http://gundigest.com/ebook-promo
DEDICATION
This is my first book without the late Dan Shideler to assist in keeping
me on track. I’m sure whoever takes over will do an exemplary job, but
his wicked and my droll sense of humor meshed quite well. I miss him.
The many readers who have told me “you have to do this” or “you
have to test that” should all give themselves a pat on the back if they see
their idea, question or even curiosity answered in this book. I tried to go
past the usual “Hey, I shot it, it’s great, you should buy it” that seems to
pervade so much writing. Oh, don’t get me wrong, there’s a lot of gear
you should buy, but I realize that not everyone has a big budget (heck, I
don’t) and buying smart is part of buying today.
A nod of thanks to the many police officers I get to instruct each year.
They offer a perspective I don’t have; that is, they in many cases don’t
care about guns. They just want the essential piece of lifesaving gear
they’ve been issued to work properly when they need it. The non-maven
perspective is useful, because someone who doesn’t obsess over the
details reminds us all there are more important things to consider: Did it
work? Is the bad guy done? Do the good guys go home?
And, to the good guys and gals who are out there at the borders, the
ones who stand a watch looking out into the darkness, or patrol
dangerous areas, looking for bad guys: Thank you.
Finally, Felicia, and the poodle dudes. My center, my oasis and pack.
CONTENTS
Title Page
Special Offers
DEDICATION
PREFACE
INTRODUCTION
ADCOR
CUTE LITTLE 300S
300 AAC BLACKOUT
300 WHISPER
CMMG .300 BLACKOUT
WILSON 762
ALEXANDER ARMS .17 HMR
DELTON TAPCO
SIG 516
STAG ARMS 3G
.223 VS. 5.56: WHAT’S THE PROBLEM?
CHAMBERING ROUNDS
HEAT ‘EM UP
SERIAL FIREARMS ABUSE
EXTRA TESTS
MAGAZINES
OPTICS & SIGHTING GEAR
SBRS, CANS AND COMPS, OH MY
DO WE REALLY NEED THESE RINGS?
PREFACE
The AR-15 seems to be evergreen. The equipment features are easy:
the modular nature of the AR lends itself to mix-n-match assembly. If
you want a single lower with several uppers, you can do that. If you
want to re-build it, you can do that. If you want to experiment (within
the bounds of legal authority), you can do that.
Therein also lies the drawback, the weakness, of the AR: anyone with
a few simple tools can get in there and screw things up. Back when I was
gunsmithing for a living, in one of the earlier assault weapons panics I
found myself with a near-deluge of nonworking ARs in need of repair.
Once I’d poked around in a few and worked out how they functioned, I
discovered that a lot of the errors were easy fixes. I had a simple price
schedule for prospective customers: If they hadn’t irreparably
ground/cut on parts, I could go through their rifle and fix whatever was
needed for $100. (This was back in the days of gasoline less than a
dollar a gallon.) If they had ground/cut something, I’d let them know
what it was, and what it would cost, before proceeding further.
The biggest reason the AR is in the hands of so many shooters,
collectors and brand-new owners comes to us courtesy of politics. With
the sunset of the Assault Weapons Ban of 1994 (back in 2004) lots of
people looked into buying ARs. They could now, so they did. They
actually could have before, but not many knew that. It is a beautiful
demonstration of the Law of Unintended Consequences.
Then, with the run-up to the 2008 Presidential Election, candidate
Barack Obama caused sales of ARs, indeed, anything that was considered
a potential object of banning, to sell like hotcakes. So effective was his
sales pitch that sales did not drop off after he was elected, at least not
until the economy soured and disposable income became not-so-
disposable.
Estimates of the DNC sales effort (which is what it, in effect, ended up
being), in some cases, have the number of AR owners doubling. Doubling.
We now have a situation where there may well be more new owners of
AR-15s than there are old hands. Which, I am not the least bit shy in
saying, is good for me and all of us if we work to make the new owners
happy and ensure they have fun and stay safe.
So, for all owners of AR, new and old hands, there are a number of old
wives’ tales, shibboleths, that must be debunked. I have done some
before, but this volume will be much different than the earlier AR-15
volumes. Yes, we’ll have some equipment reviews; after all, we’re all
addicted to this particular rifle, and we have to know what is new in
rifles, optics, ammo and associated gear.
But the main focus of this volume will be testing and abuse. I will be
testing ARs in ways that you will not have read about except from
declassified government testing. I must admit, and warn you, I do not
have a multi-million dollar lab in which to test rifles, so there are limits.
I cannot test to destruction although I do come very close in some
instances. For example, I have in my hands (well, on my hard drive) a
report the government did to test M4 barrels. They put the rifles in a
fixture and slammed full-magazine full-auto bursts through them until
the barrels essentially melted. The barrels became over-heated and soft,
sagged, and bullets exited the side of the barrel, thus ending each test.
“What the frak?,” you ask? Why do that? Simple: in a military context,
someone, somewhere, is going to use an M4 as an impromptu SAW, and
the government would like to know how long that usage would last.
Answer: a bit less than 400 rounds, depending on ambient temperature.
Me, I did a less-abusive and more likely test, and measured
temperatures, since it is unsafe to melt barrels while firing rifles unless
they are locked in an armored room at the time.
But, I buried them in dirt and sand, submerged them in water,
dropped them from heights, ran over them with various vehicles, froze
them and shot them with damaged ammo to get an idea of how much
abuse they can withstand.
When I was done I was still left with a question: Where are all these
unreliable AR-15/M16s I’ve been hearing about? Because it was very,
very hard to get them to malfunction and, short of damage, they
wouldn’t quit.
INTRODUCTION
WHAT ARE WE TRYING TO DO HERE?
There are a number of laws that run the universe. We are all familiar
(or so we think) with Newton’s laws. Inertia, action and opposite
reaction, and so on. That heat propagates through an object, and
dissipates, and the gases expand or contract, according to the whims of
the moment and how much energy we pump into the system.
All true, and all relevant. If you do not know, for instance, that
Newtons’ First Law means your bolt will stay in place until the gas or
piston works on it, you will be woefully un-prepared to keep it running.
But there are laws we are subject to, that work in the real world, that
have not really been codified. Some because it would be an impossible
task to nail them down. Others because to nail them down would seem
to obviate free will.
Perhaps the most famous is Murphy’s Law; “If anything can go wrong,
it will. And usually at the most inopportune time.” You’ve planned for,
and looked forward to, a particular match for a long time. When will