Slam Fire

[Sherri]

Today at the range, the gun went bang, bang, and then click. I waited a bit, then dropped the magazine and locked open the slide. What popped out was a peppered round (the primer was dinged). I used my flashlight to confirm a clear barrel. I loaded that dinged round into the top of the magazine, smacked the mag home, racked the slide--and it went off. Yikes.

I don't understand what happened. Can anyone offer an explanation?

More information... Sorry for the incomplete initial post.

The pistol is a SA Champion .45. I've run maybe 400 rounds through it with no trouble. The first 100 were factory rounds, the rest mostly reloads.

After the slam fire I dropped the magazine and locked the slide open. When I'd calmed down, I loaded the magazine and fired the remaining few rounds, and subsequently fired two more magazines with no troubles.

I've examined the spent brass I brought home and the primers all look to be properly seated.

 

[MICHAEL T]

What type of pistol is this. Also MAKE SURE UNLOADED AND STOP SHOOTING It needs serious attention . warranty or gunsmith

 

[Jeff82]

deleted

 

[MICHAEL T]

racked the slide--and it went off. Yikes.

Iam look more at pistol She dropped slide and it fired . Bad Sear, firing pin stuck ?
Don't think ammo

 

[GLOOB]

Inertia causes the firing pin to follow through when the slide closes. Many designs have a firing pin safety which blocks this. Most 1911's rely on the firing pin spring to prevent this. I'd take this part out and check it. Actually, you don't even have to take it out. Just unload the gun, cock the hammer, and press on the back of the firing pin to make sure the spring is good.

Possible explanation: on some previous shot, the FP spring broke. The misfire occurred because on that particular shot, the FP came to rest just exactly where the broken spring ends, and just far enough forward to be hidden from the hammer. The hammer struck the back of the slide, not even touching the firing pin. The ding was probably already there from the FP follow that occurred when that round was chambered. The round may have been pre-sensitized by the dimple, making it go off on the second chambering. Or maybe when you dropped the slide manually, it had more force than when you are actually firing it. And this particular primer got just enough of a hit to light off, unlike the remaing 2 mags.

I'm just stabbing in the dark, but this theory explains the coincidental light strike. Of course, if this was the case, you probably would have noticed a primer dimple on every subsequent round, if you had bothered to check.

The Makarov pistol has neither firing pin block nor spring. It is common for chambered rounds to have a primer dimple. It is not recommended to load the same round several times, because this dimple can and will get deeper with each chambering.

 

[Sherri]

Hey, GLOOB.

I'll perform the firing pin checks you suggest tomorrow. I may take the firearm to a gunsmith before I take it to the range. I'm still thinking it through.

My good friend and mentor was with me at the range yesterday. When the pistol went click, I waited, dropped the magazine, and cleared the chamber. For good measure, I shot a flashlight down the barrel.

We examined the round that failed to fire--the primer was well dimpled. Neither of us made notice of a poorly seated primer (and I examined my spent brass today--it all looks fine in that regard, although I cannot say for certain that the slam fire case was amongst those retrieved--yesterday was a particularly poor day for retrieving brass, and frankly, the slam fire introduced some confusion).

I also put the hairy eyeball of the remainder of that batch, looking closely at primer seating. I had primer feed issues when I loaded that batch, and I retrieved and used spilled primers from a less than pristine can sitting under the press. These rounds were so labelled, and so my suspiscion of primer failure was raised when a round failed to go off.

We racked the rest of the rounds through the pistol and examined them. There were no indications of FP contact. There did seem to be very slight nicks on the plated bullets, so they're not feeding perfectly. But still.

This afternoon my friend shared 3am thoughts that perhaps the dimpled primer was compressed in a way that the jarring of being chambered was enough to set it off. And he voiced concerns about the FP spring.

There's lots to think about here.

Thank God I was exercising good muzzle control--the errant round blasted my PVC pipe target stand. I'm not sure. I must have shot a puzzled (shocked?) look at my friend, but I kept the muzzle down range, and my finger outside the trigger guard. Had the pistol gone full auto, I'm not sure I would have had the presence of mind to keep it under control. Now, I think I do. Or at least my mind is open to the possibility. I will never again rack a slide without being mindful that it may go off, and perhaps repeatedly. And a discussion of this will be part of what I have to say to a new shooter before they pick up a .22 revolver and fire their first shot.

Thank you for the thoughtful response.

 

[FlyinBryan]

i dont think this pistol has a firing pin safety like a series 80 colt (trigger activated) or a kimber series2 (grip safety activated)

 

[Drail]

Primers really do need to be seated all the way to the bottom of the pocket (and a couple of thous. below the case head). Examining the primers after they have been fired won't really tell you anything useful because the firing pin will finish seating the high ones as they are struck. If the round went off when being chambered and the hammer remained cocked it would indicate to me that the firing pin spring has weakened and needs replacing. The only other possibility I can see is that the previous attempt to fire the cartridge which dimpled the primer left the primer in a condition where the anvil was so close the dimple that inertia caused it to fire. (almost impossible) Every time you rack or drop a slide EXPECT the gun to fire. It probably never will but now you know what can happen and why instructors are so adamant about muzzle discipline. How heavy of a recoil spring are you running?

 

[Skylerbone]

If it will load an empty casing (with spent primer) or you have a snap cap try racking the slide then releasing it and see if the hammer follows. Do not perform on an empty chamber.

With 400 rounds I would suspect the pistol.

 

[Ragtop5969]

If I recall correctly, S/A 1911's use a 9mm titanium firing pin and a heavy duty firing pin spring to pass drop test and CA requirements and prevent problems.

The other serious problem with S/A is that they refuse to sell replacement parts and there may be some after market replacement parts in that gun causing the problem.....

 

[Drail]

If I needed to replace ANY parts in a SA I wouldn't even consider replacing them with SA parts. Go aftermarket. Wolff springs. Extra power.

 

[Sheldon]

The round that appeared to slam fire may have just been a bit sensitive from having been previously struck....this is the reason I don't use a kinetic bullet puller to further aggitate a round previously primer struck.

 

[murf]

let me try: 1) primer not fully seated. 2) when trigger pulled, firing pin dents the primer cup and pushes the primer core foreward against the case's primer pocket. 3) upon chambering the round a second time, the slide shoves the primer cup into the primer pocket contacting the cup and detonating the round. (sounded good to me)

murf

 

[NMGonzo]

firing pin stuck forward?

 

[Ragtop5969]

If I needed to replace ANY parts in a SA I wouldn't even consider replacing them with SA parts. Go aftermarket. Wolff springs. Extra power.

Where do you get a titanium 9 mm firing pin that S/A likes to use?

 

[1911Tuner]

Today at the range, the gun went bang, bang, and then click. I waited a bit, then dropped the magazine and locked open the slide. What popped out was a peppered round (the primer was dinged). I used my flashlight to confirm a clear barrel. I loaded that dinged round into the top of the magazine, smacked the mag home, racked the slide--and it went off.

The clue is in the first sentence. It suggests that you've got a problem with the disconnect. Specifically, it's not resetting due to interference with the sear leg, and in turn causing the sear to fail to reset completely into the hammer. It "stages" itself on the very tips of the hammer hooks, and when the slide goes home...it jars off.

Because the sear is held by the disconnect and can't reset...it doesn't fall into the half-cock or quarter cock shelf...whichever the gun happens to be equipped with...and the gun fires.

The cure could be as simple as stoning a burr off the sear foot or the top of the disconnect paddle...or it could require replacement of one or both parts.

There's also a chance that this was a hang fire. Most of the time, they go off within 30-60 seconds, but I've seen'em take as long as about 2 minutes. I was present for one such. The guy waited as required....ejected the "dud" and placed it on the table to reclaim the bullet and case...and fired two complete magazines before it detonated. Luckily, no harm was done, but it did scare the soup outta both of us.

Get thee to a smith before loading the gun again.

 

[243winxb]

To light a trigger, sear ingagement. Hammer follows slide down. Make sure sear/hammer is free of oil & never use a Teflon product on your lite trigger pull gun. <This alone may correct your problem.?? Another sign-let the slide slam on an empty chamber, this will sometimes cause the hammer to drop also. Weight on a 1911 type trigger should not be below 3 1/2 lbs IMO.