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View Full Version : Dry firing, what happens????????


fred1814
02-08-2005, 7:09 PM
why is dry firing bad? what happens to the gun? why do you need dummy runs

fred1814
02-08-2005, 7:09 PM
why is dry firing bad? what happens to the gun? why do you need dummy runs

Technical Ted
02-08-2005, 7:14 PM
Used to be an issue of firing pin breakage. Not really an issue for most modern guns. With the exception of rimfire rifles (See, with centerfire the pin isn't apt to hit anything but empty chamber) .22 LR rifles are susceptible to firing pin breakage.

LongBch_SigP226
02-08-2005, 10:07 PM
That's what the snap cap is for no?

gunsmithcat
02-08-2005, 10:08 PM
ive only been told this and do not honestly know from personal breackage/experience..
but with rifles its generally ok to dry fire

However ive been told to use snap caps with handguns

wheelgunner
02-09-2005, 3:51 AM
Older Smith & Wesson centerfire revolvers, and some others firing pin is fragile and could potentially break or crack if dryfired on empty chamber. I believe the newer Smith & Wessons have a transfer bar system similar to Ruger.

22lr is generally not a good idea, rim is supported by "rear" cylinder face or breech. Firing pin may strike "rear" if dry fired, breaking/damaging firing pin (steel striking steel), or damaging "rear" face.

Center fire rifles, I have not heard or read of which is OK or which is not OK to dryfire.

The centerfire Ruger revolvers and pistols that I have, owners manual states to practice dryfiring.

Recomend to check with manufacturer if its OK to dryfire with your particular firearm be it pistol, revolver, rifle, or shotgun.

If in doubt: For centerfire inexpensive snap caps or home made empty-deprimed case primer pocket filled with silicon rubber gasket material. For 22lr, a "FIRED" case (EMPTY, no bullet or primer compound) will work. Don't use 22lr fired case more than once, firing pin will peen the rim and case may get stuck in chamber (don't ask how I know).

jnojr
02-09-2005, 9:51 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by wheelgunner:
Older Smith & Wesson centerfire revolvers, and some others firing pin is fragile and could potentially break or crack if dryfired on empty chamber. <HR></BLOCKQUOTE>

Why would a firing pin "break" or "crack" when actuated against empty air, but not when it's slammed into a piece of metal???

Turbinator
02-09-2005, 12:06 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by jnojr:
=Why would a firing pin "break" or "crack" when actuated against empty air, but not when it's slammed into a piece of metal??? <HR></BLOCKQUOTE>

If I understand correctly, the problem isn't so much the firing pin hitting air. For revolvers that have the firing pin machined into the hammer, dry firing allows the hammer to slam unnecessarily against the frame of the revolver, rather than having the force of the falling hammer taken up by a snap cap or a live round. When this is done repeatedly or excessively, you can stress the frame and potentially cause cracking.

This is my conclusion based on reading about this many times over. Your mileage may vary.

Turby

wheelgunner
02-09-2005, 7:26 PM
I searched for an immage of a Smith & Wesson but to no avail.

Here is an example of a hammer mount firing pin that is not as strong as frame mounted.
http://photos.ar15.com/ImageGallery/Attachments/DownloadAttach.asp?iImageUnq=35352


Picture of Ruger frame mounted firing pin with transfer bar safety.
http://photos.ar15.com/ImageGallery/Attachments/DownloadAttach.asp?iImageUnq=35353

I have never seen a firing pin break on hammer mount. I have been told by old/vetran shooters and an old/vetran gun smith. Hell, maybe its an old wives tale http://calguns.net/groupee_common/emoticons/icon_eek.gif

To find out for sure about a particular firearm, contact manufacturer and/or look in owners manual. http://calguns.net/groupee_common/emoticons/icon_biggrin.gif

imported_booknut
02-09-2005, 8:18 PM
All of my new (199_-something) handguns can be dry-fired per the manual.
I still use blast caps...er I mean snap caps...hehehe...
If I'm doing dry practice then I'm usually working some drill so I like to have rounds that I can eject/unload and reload with. (some folks say you ONLY fire a weapon with live ammo but you DRY PRACTICE without. Sounds a bit nitpicky but I'll go along quietly)

From a strictly engineering standpoint, as the firing pin moves forward, if there is no obstruction such as a round of ammunition, then a small but high-velocity puff of air is driven into the chamber area and/or barrel. This 'puff' of air meets resistance as it travels along toward the muzzle and consequently slows down and also does not track in a straight line. What this does is it sets up a 'stale air' environment robbing the barrel air of some oxygen storage capacity. Now keep in mind that modern firearms ARE engineered to exacting standards and the gas atmosphere in a barrel is carefully calculated. Once you've thrown off that complex mix, you create a 'low O2, high Noxicity' situation whereupon the next time you fire a live round, incomplete combustion will transpire causing the moving projectile to wander aimlessly about the inner reaches of the barrel POSSIBLY even reversing direction creating an 'implode load' which MIGHT re-route the energy dynamics and force the casing into the firing pin causing fracturization of the crystalline metal structure.

But then...I'm not an engineer (but I DID ride on a train once! http://calguns.net/groupee_common/emoticons/icon_biggrin.gif )

Sorry...just feeling a bit goofy tonight!

BigRich
02-09-2005, 8:28 PM
Booknut,
It sure pays to follow this forum. All along I thought that firing pins broke because the back of the pin stopped and the front wanted to keep going, causing attempted elongation and breakage resulting from a lack of elasticity. I would never have known that it was from an improper gas mixture in the barrel. Boy do I feel like a fool. Thanks for educating me. http://calguns.net/groupee_common/emoticons/icon_biggrin.gif

Technical Ted
02-09-2005, 8:31 PM
Wow Booknut, did you stay in a Holiday In Express?

imported_booknut
02-09-2005, 9:13 PM
Bigrich,
Easy there fella! I'm sure you know something I might not know.
Don't feel bad.
What you are referring to is 'Dynamic Separation in Acute Linear Halting'.
This is common among the older guns (older than my 199_something's).
Because of the propensity for firing pin manufacturers to cut corners AND because so many firing pins were contracted out of countries with decreasing latex exports, many of these pins were made in the same plants where rubber was made. Hence the commonly used term, 'GoodYear...BadPin'...I'm sure you've said it a thousand times yourself.

Chemically, the pure latex combined with the raw iron crystals prior to heating and forging. But, because of poor quality control, the rubber (which should NEVER have been introduced into the mix), was aged to a point where the strand mitrification degenerated to the point where incomplete cohesion with the steel left fissures which weakened an already soft structure.
You're following alright aren't you?
So on the OLD firearms, you are correct.
The pin is essentially 'stopped', (we like to use the term Acute Linear Halting) leaving sufficient forward motion which attempts to elongate the combined materials. The weak fiber structure having no residual strength in the 'latex-steel' complex essentially 'snaps' causing seperation at high speed.
We're just darn lucky no one has ever been killed by that little tip of the firing pin!
You're not as uneducated as you seem...er, I mean think you are! http://calguns.net/groupee_common/emoticons/icon_biggrin.gif

TechTed,
No and I don't even know where Express is? Is this in California?
I did stay in a Holiday down in Monterey once though!
Thanks for asking

Technical Ted
02-09-2005, 9:23 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by booknut:
TechTed,
No and I don't even know where Express is? Is this in California?
I did stay in a Holiday down in Monterey once though!
Thanks for asking <HR></BLOCKQUOTE>
A wise guy, ay? Why I oughta...shoulda checked my spelling of Holiday Inn Express http://calguns.net/groupee_common/emoticons/icon_biggrin.gif

Rascal
02-09-2005, 9:43 PM
Alright! you guys owe me a new keyboard!!!
And do you know how hard it is to get coffee stains off of my cubicle walls? http://www.calguns.net/laughroll.gif
[wipes coffee off of terminal while trying to avoid sparks coming form keyboard]

imported_booknut
02-09-2005, 9:58 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by Technical Ted:
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by booknut:
TechTed,
No and I don't even know where Express is? Is this in California?
I did stay in a Holiday down in Monterey once though!
Thanks for asking <HR></BLOCKQUOTE>
A wise guy, ay? Why I oughta...shoulda checked my spelling of Holiday In_n_ Express http://calguns.net/groupee_common/emoticons/icon_biggrin.gif <HR></BLOCKQUOTE>

Nyuk, Nyuk, Nyuk...I'm tryin ta think, but nuttin' happens!

ivanimal
02-09-2005, 11:04 PM
TMI TMI TMI I need air ineed air...................