Talk:Slamfire

Slamfire - comment....
Slamfire normally only occurs in a weapon that is designed to fire from a closed bolt, in other words where the bolt closes on the breech and a striker or firing pin strikes the percussion cap as a result of the trigger being pulled. Slamfire occures when the pin becomed jammed in the forward position and intiates the round as the bolt closes.

Most machine guns fire from an open bolt, in that the bolt only closes when the trigger is pulled. This means that a waiting round is not held in the potentially hot breech. Sub machine guns such as the STEN and the MP40 also have a fixed firing pin. When the trigger is pulled the bolt is released and flies forward, stripping a round from the magazine and feeding it into the breech. The primer is actually struck BEFORE the round is fully chambered and the propellant is ignited as the round moves forward. This is known as "advance primer ignition" and is a design feature of this class of weapon, which allows a lighter bolt to be used. This could be referred to as "slamfire" but is not the traditional use of the term. An automatic weapon continuing to fire when the trigger is released is generally referred to as a "runaway gun" not a slamfire.... —Preceding unsigned comment added by HE117 (talk • contribs) 08:31, 24 November 2008 (UTC)

Picture? Diagram?
Any kind of picture or diagram would be very helpful to the article. Piano non troppo (talk) 19:33, 29 December 2008 (UTC)

Slamfire by design?
Any thoughts on a section regarding crude firearms that intentionally fired via slamfire? Examples include Philippine Paliuntod (WWII era) and SWD Terminator (1980s). -- Surv1v4l1st (Talk 03:58, 21 July 2009 (UTC)
 * Sounds like a good idea. There seem to be any number of expedient (or covert) type firearms that work this way.  Kartano (talk) 23:03, 28 January 2010 (UTC)

Auto sears vs slamfire: Much confusion
"Slamfire" refers to:

(1) the operation of fixed firing pin designs (usually blowback submachine guns firing from the open bolt) that fire as the floating breech bolt nears battery while moving forward under spring pressure.

(2) analogous malfunctions that occur when a gun discharges either (a) without being in battery, usually due to the firing pin being stuck forward, or (b) when the hammer has followed the bolt carrier group forward as the gun goes into battery, like an M-16 with the auto sear removed.

Guns that have sears that drop their hammers **by design** when the gun goes into battery, like Ithaca 37's and M-16's, are not "slamfiring." They are meant to do that. You don't say an M-16 is "slamfiring" in auto and the Ithaca 37 is no different. Like the M-16 hammer, it actually has a hook on its hammer that holds the hammer back even though the trigger has not reset and releases it when the gun reaches battery. This is the very antithesis of a slamfire.

07:13, 12 February 2017 (UTC)Criticality (talk) 07:13, 12 February 2017 (UTC)


 * I have removed the following text describing pump action firearms firing as the breech closes only if the trigger is depressed, in the hope this will clarify the distinction from slamfire independent of trigger activation. Thewellman (talk) 17:56, 11 February 2019 (UTC)
 * Many early pump action shotgun designs such as the Winchester Model 1897, Winchester Model 1912 and Ithaca Model 37 lacked a trigger disconnector. Combined with a second sear that allowed the hammer to strike as soon as the action was operated if the trigger was still depressed, this allowed for such a shotgun to fire as fast as the user could pump the action. 
 * Some pump action shotguns, such as the Ithaca Model 37 are designed to slamfire for higher output of shells and thus damage. These designs may have the trigger held down as the pump is cycled to reach a rate of fire similar to a semi-automatic weapon.


 * The Winchester Model 1897 shotgun was deliberately designed to be slamfired by holding the trigger and operating the pump. This permitted a soldier to rapidly spray shells onto a target area (such as when attacking a trench). Ithaca 37 shotguns were used by US Navy SEAL units during the Vietnam war due to this capability.

Possible Solutions
Not mentioned are devices which hold the firing pin. Although mostly designed as a safety in case of a dropped pistol, they should just as well inhibit slamfire. I suppose all modern pistols have something of the sort. IIRC the CZ 75 for example has a vertically sliding block, which lets the firing pin move freely only if the trigger is pressed. Won't help against the fouling issue mentioned in the article, but will certainly help with sensitive primers. Do I see this correctly or did I miss something? --BjKa (talk) 11:18, 12 September 2018 (UTC)