Sunday, June 10, 2018

1911 Failure

So what caused this failure?

Goodness know, I am guessing.  I'd have better luck guessing if I had the actual gun in my hands.

One guess is that the bushing was tight and spring the barrel, causing stress to the slide that way, and it just gave way.   It seems to be breaking from the muzzle back, so that is why I think this.

But if there is one thing I have learned with 1911 gunsmithing, the problem is the opposite of what you are looking at.  Like:  "The round is stuck on the feedramp.  Must be the feed ramp."  Naw.  That's prolly the extractor, at 180 degrees of what you are looking at.

So if it ISN'T the bushing, then it is maybe something with barrel lockup.  The barrel didn't fit well, maybe, and peened the softer upper lugs and that caused problems leading to the slide splitting?  I like the bushing fault more.


B said...

It looks like it goes through the dust cover too though, so I dunno.

New Jovian Thunderbolt said...

So maybe a springing barrel bushing can account for the top split, but the bottom less so? Perhaps... I can see where you are coming from.

B said...

I'd like to see the bushing, too

Paul said...

If one replaces the link with a 'match' one it can force the barrel up to far and crack the slide, or rails, or both.

New Jovian Thunderbolt said...

Ooo! Good one Paul. Poorly fit bottom lug link. But the spread is still greater up toward the muzzle.

Will said...

the photo perspective can make it look odd. The slide is cast, judging by the granular surface near the muzzle end. Not enough data to determine which end initiated the fracture. It's possible the crack started at the front sight cut, and spread due to recoil forces at the rear end. More photos needed!

pigpen51 said...

I can't tell for sure what caused the failure, but I bet a contributing factor was improper heat treating of the parts. The slide and frame look to me to be cast, and since I made steel for the investment cast industry for 35 years, I am going out on a limb and guessing that the alloy is 17-4, with the barrel being made of either 410 or 416. Those last two alloys are actually very much the same alloy, however the 416 has always got sulfur added to it to facilitate machining since it makes the turnings come off the lathe in chips, instead of long spindly things. The other element that can help do that is Selenium, which is commonly used in 300 series of stainless.
A metallurgist and an engineer working together could probably figure out the reason that the gun failed. It does such to see such destruction of a nice gun, though.