From rec.guns:

"Clint & Thomas,

Well said.  Thomas, thank you again for your courage in relating this story.
As a doggie daddy for many years, I can feel your loss.  Clint, thanks for
the kind words re: my book.

To this day there are those who don't believe slam fires can happen.  They
can and do, and of all the US military and military-type gas guns, the AR
seems most prone to slam fires.  It may be due to the lack of primary
extraction in reverse.  With the Garand action of the M1 and M14/M1A, the
bolt sort of screws its way into place.  The AR, on the other hand,
basically slams the bolt home and then turns it.  There's less of a
cushioning effect.  It took the Army and Colt many months working with
Remington to solve the problem, which to them was reducing the freqency to
what they felt were acceptable levels.  As civilians, our acceptable level
is zero.  Not so for the military, as Clint so eloquently observes.  With
the original firing pin, Remington found by varying primer hardness they
could achieve 50% slam fires with no failures to fire, or 50% failures to
fire with zero percent slam fires.  My book illustrates the older, heavy
firing pin & contrasts it with the one finally adopted.  This newer pin
reduced slam fires to an acceptable level in conjunction with a slightly
heavier primer cup.  BTW the "heavy" pin came out of Colt AR-15 SP1 #1086!
Good thing I don't shoot that early "collector" AR!

BTW current CCI military #34 small rifle primers for AR-15 use don't
actually have a heavier cup, as do their #41 large rifle primers for the M1
and M14-type rifles.  The #34 positions the anvil away from the bottom of
the primer pocket, so that the firing pin has to seat the anvil before the
primer detonates.  That's what gives the extra resistance to slam fires.
This illustrates the fine balance among firing pin design, firing pin
weight, and primer design.

I will guarantee you that American Eagle .223 ammo does *not* have mil-spec
primers.

Folks, *never* cycle ammo through a US military gas gun, unless you're at a
range and pointing down range, or have a snail as does Clint at Fulton
Armory.  At my own facility (300 miles from Fulton Armory), a live round has
*never* been chambered in a US military gas gun.  *Never*!  I'm scared to
death of what happened to Thomas.

Our current "defense gun" is a Fulton Armory FN Police Shotgun, with a six
round sidesaddle.  That's the only live ammo anywhere near a weapon here.  I
figure the dogs will give ample warning, should it be necessary to repel
boarders, allowing the transfer of six shells from the side to the mag of
the shotgun.  If a threat presents itself, there's nothing more intimidating
than hearing a pump shotgun being racked, and seeing a the muzzle of a .72
caliber carbine!

As a kid, I learned in Scouts that every gun is loaded.  One's first action
on being handed a gun was to make certain that it was indeed empty, both
magazine (or cylinder) and chamber.  Alas, as Thomas found out, the very act
of chambering a round in a US military-type gas gun can result in tragedy,
which makes the second rule so important: never point a gun at anything
you're not willing to shoot.

Again, Thomas, thanks, and I'm truly sorry for your loss.

Best regards,

Walt Kuleck (with Darby and Duffy)"
Fulton Armory Webmaster
http://www.fulton-armory.com

Unfortunately,
I don't have access to newsgroups at the moment, what was the preceding post?

I know it must have been about the loss of his dog due to a slam fire, just wanted to see the rest.

I have seen and shot many thousands of rounds thru M16 AR15 and never seen or had a slam fire. That being said you should NEVER cycle live ammo thru any gun unless you are at a range and pointed in the right direction.

Slamfire?  Never even heard of it in an AR.  Sure the guy didn't have his finger on the trigger?

Reminds me of the cop that hit his hammer drop on his sig and the gun fires?  I'm sure that it was his trigger he hit and not the hammer drop lever.

OLY has a firing pin return spring they use in their pistol cal. conversion,for AR's it may solve any and all slam fire risks!

The only access I have right now doesn't show threads, misterhemi.