A buddy of mine picked up a 4506 up for next to nothing as it was advertised as having a cracked frame. I stripped it down for him and couldn't resist, with his permission, posting a photo of the frame.

The slide, barrel, etc. appear to be undamaged and the pistol seemed to function fine. It probably would have fired, but we have survived enough "I wonder what this would do" events in our younger years to continue down that path.

I've never seen this extent of damage on a 3rd gen steel frame gun, and I haven't a clue what caused it.

Attached Images

image.jpg (69.1 KB, 719 views)

My guess would be that the crack started where the numbers are stamped, possibly from hot ammo, and went from there.

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1st smiles,lies.Last,gunfire.

Stepped on? Run over while laying on the pavement?

Over tightened in a vise????

Interesting.

Does the crack continue thru the opening
(slide stop opening?) and up thru the slide
rail?

How's the starboard side look?

I think the crack originated here and propagated with continued use/firing:


I understand cracks developing at the frame step was a known issue with the no-dash guns which, in part, led to some of the engineering changes we saw in dash-1 guns.... ie. deletion of the frame step, narrowing of the camming lugs & feedramp on the barrel with accompanying thickening/strengthening of the frame section through this entire area.

Cheers
Bill

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Because they don't make a .46

I've seen locking block 'stop' cracks
start at frame-pass thru holes.

Is that hole (above S/N markings) where
the main 'stopper' passes through the frame?

Looks like some peening on the back side of
hole, just aft of the S/N hole (sorry for
terminology, not acquainted with that pistol).
Possibly a 'non-load bearing' part that started
taking up the slack, after crack propagated?

Yup, that's where the slide stop crosspin goes through. That pin is the bearing surface the ramps/lifts the barrel into engagement with the locking lugs in the slide then brings everything to a sudden halt once lockup is achieved in battery. Impact forces on that pin as the top end runs into battery are directly transferred into the frame at a forward and down angle. Extra power recoil springs can be a contributing factor to cracks and/or peening in this area along with peening & premature wear of the locking lugs.

I'm curious to see what the other side looks like.

Cheers
Bill

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Because they don't make a .46

One of my 3rd Gens had a "too loose" slide stop pin that started backing out while I was shooting it at the range. Fortunately I noticed it before it backed out too far but I wonder if one backed out too far would it stress/crack the frame at the slide stop hole on the left side?

.

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Waiting for the break of day

I suspect that it was run over or something fairly heavy was dropped on it. Because the cracking appears to consist of a patter that would be produced by dropping something like a bowling ball on the frame after the slide had been removed. Lesson here is don't have your bowling ball parked on the table while cleaning your pistol.

PS; I will admit to listening to J Geils' "No Anchovies Please" not too many days ago.

Yeah, I vote with the external impact damage crowd. No expert technical or scientific reason. Just my guess based on the pattern of the damage.

Perhaps this pistol was used as a 45 Super.

That's not from shooting damage, it has been run over by something. If it was from shooting I would think there would be peening around the slide stop hole in the frame. The hole on this one just looks to be shattered. I have seen about a dozen cracked S & W frames on the range, plus our agency had about 40 frames crack on our 4056 Tacticals, but that was a whole 'nuther issue. Almost all of them cracked that cracked from shooting cracked in the groove where the slide rails run or around the side plate hole. For that frame to have cracks in that pattern and especially to extend in more or less a straight line across the frame cut out, Im confident it had significant external force applied to it.

That's what the pictured frame has...

Looks like S&W counterbored that hole (and probably fattened
up the base diameter of the slide stop pin--maybe had some
problems with them snapping off?) and the thinned portion
from 1:30 to 5:00 is *gone*.

Maybe she done got runned over (external portion of slide
stop acted as lever, and broke out thinned portion of frame),
with no casually apparent damage; pistol was fired, and
11:00 crack developed in stop hole...

When I said cracked in the groove where the slide rails run, I meant they cracked linearly down the race way. The hole that is cracked isn't the slide plate hole. The hole where the pin for the slide plate runs through is the furthest hole to the rear. You can see the imprint of the slide plate lightly in the rear of the frame in the photo.

In response to questions regarding the other side of the frame, it looked completely normal; so much so that I didn't take a photo of it.

I I were to venture a guess...

It would be a bunch of full powered loads fired with the light target load recoil spring.

John

Must be one of those guns that got shot out of the bad guy's hand like you see in the old movies and TV shows.

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My sgntr is mor thn 30 chrctrs

There was an incident on the west coast where an officers 4506 was struck by a 40 round fired by a miscreant who was trying to kill the officer.

The 40 struck the left side of the pistol shearing off the slide stop and left side decocker paddle. The officer was still able to return fire with his damaged 4506 and killed his attacker.

As to this 4506 I think that both groups are right. Probably shot a bunch, with a wad cutter spring instead of the proper spring. Probably hot loads and a bunch of them.

And then the damaged frame was subjected to additional external force. I have never seen any handgun frame with cracks like that from just shooting it. My 0.02 Regards 18DAI

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7 +1 Rounds of hope & change

Bubba the Gunsmith strikes again!

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Can open, worms everywhere.

Somebody fired a 40 S&W and blew out the case.

Have been in failure analysis for many years, I would have to agree with the impact line of thought. The crack is way too long to have been caused by firing. A large force was placed upon the frame in the area of the rails which caused the crack.

Could it be a frame which was "destroyed" by some police department by crushing with a bulldozer and somehow escaped the melting pot?

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Bill

From post #1...

I don't see any obvious concavity in the picture nor any serious deformation other than some minor vertical displacement of the port side rail. This observation and the wording from the OP led me to discount impact or crushing as the cause. I have to assume if the slide were run over or crushed by some lateral force, the resulting deformation would not permit the slide to run on this frame at all. However the OP observed it appeared to function fine so I explored what could have exerted excessive upward force at the front of the rails.

I kinda view this as an entertaining mental exercise in trying to figure things out. But when it comes right down to it we're all just guessing about the cause here. Still, it would be interesting to find out just exactly what happened but I kinda doubt we'll ever know. Harpy speculating

Cheers
Bill

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Because they don't make a .46

Still looks like frame damage from a blow out to me..

Personally, I'd love to see the slide stop. I'd be willing to wager that if it is distorted then I'd say it was a lot of hot loads with a light recoil spring. I'd also back that up with the appearance of the crack itself, which is linear in the same direction as the recoil impact forces.

If it was caused by pressure (shop vice, running it over, etc.) I wouldn't expect to see the crack in that area - especially with no damage to the opposite side. And I would expect that it would have to be something very heavy and without rubber tires or treads. Perhaps a multi-ton shop press?

As for momentary impact damage on the side I would expect to see a definable impact point and any cracks radiating out from there instead of linear in a single direction. And based on location, I would expect to see damage to the slide as well - although we are told the slide is in good shape.

The only thing I can say at this point is I wouldn't count on the slide, barrel and slide stop being in as good shape as a casual visual inspection would lead you to believe! This kind of damage is seldom isolated.

And that's a far as my Statics, Dynamics and Strength of Materials classes in college take me.

Not possible. A .40 S&W round in a 4506 would go PFFFFT and wouldn't get anywhere near full 35k PSI spec of the .40cal round. It must be fit in a chamber that holds it to size for the pressure to build properly. A .40cal in a .45 chamber will go "BANG" but with much less fire and fury than a .40 S&W in it's own .40cal chamber.

Bingo, I do believe. Either that or some "adjustment" with a heavy hammer.

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Pisgah

I don't know about the rest you, but that picture is going to give me nightmares!

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Can open, worms everywhere.

Fer sure!

The hot loads and a light recoil spring theory doesn't wash either.

Firing 45 super or even 460 Rowland in there with no recoil spring at all would not damage the frame in this fashion.

At the end of rearward slide travel the slides spring tunnel impacts the frame's impact abutment which is right above the root of the trigger guard a quarter inch forward of the frame rails down inside the dust cover.

Heavy loads with no spring at all, one might see some peening on the impact abutment and the rear face of the spring tunnel and at the very worse possibly a fracture on the slide at the top rear of the spring tunnel... And I emphasize might as it's much more likely you would see no ill effects at all. I have seen an old GI 1911 shot without a recoil spring with no ill effects at all. The 4506 is a significantly stronger design so I don't believe the weak spring theory has merit regardless of load power.

I wonder if the OP couldn't give us a couple more pictures... I'd like to see a view looking straight down at the top of the frame to assess parallelism of the rails and if there's any concavity on the left side. A shot of the right side would be nice too if it's not too much trouble. It's a puzzle alright

Cheers
Bill

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Because they don't make a .46

I'd like to have a better look down inside the L/S of the frame, around the slide stop lever assembly's pin hole.

I've never seen a frame where the hole for the slide stop assembly's pin displayed that much missing steel from inside at the rear of the hole. Makes me wonder what sort of (repetitive?) forces were acting on the frame and the lever assembly's pin at some point.

Also, the cracked frame above the sear pin is kinda odd, as is the downward angled surface marring in the frame behind it.

There may be more than a single causative event/force involved in the destruction of that frame.

Being able to see what the original slide stop lever assembly looked like, as well as the slide, barrel and guide rod (presuming all were actually original to that gun when it came off the line, and not at least the barrel having been replaced at some point by someone wanting to shoot .45Super) might be interesting to consider.

The original .40's were reported as sometimes experiencing some cracked frames and barrels over extended service use. The CHP detailed their experiences in a memo written back about '05, when they finally decided to replace them with the newer and stronger TSW models. The .45's (4506's) weren't exactly known for being "light-duty" guns, and when they introduced some revisions from some lessons learned from their experiences with the 1006's, they became even better.

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Ret LE Firearms inst & armorer

I don't have ready access to the frame and other parts at this time. When I am again able to take some photos, I will post them.

I am no expert, but one would have to assume that if a crack began in plain sight on the frame, no one in their right mind would keep shooting it until pieces began to chip off of the frame. My vote is impact vs wear/tear/abuse. ffr1910

Since we have a limited view of the frame, let's take a further look at the pic we have. Notice that the hole for the frame stop is counter-bored, leaving a thin shoulder of metal. You can see that there is a V-shaped chip in that shoulder at about the 10:30 mark, and V-shaped cracks or chips are like an arrow pointing back and forth along the direction of force. It's also pointing directly at the weakest point - where the groove for the slide cuts off the top of the counter-bored outer circle leaving a step and small right angle cut in the circle.

The crack then leaves the hole for the frame stop at about the 5:00 mark and interestingly passes thru the rollmarked serial number. Now we know that when stamping marks are applied they stress the metal's molecular structure - and dollars to donuts says either a microfracture was initiated or aggravated when the roll marks were applied. Follow the crack down and to the right and you can see another V-shaped crack pointing along the direction of force.

Now I'm not a gunsmith so I don't know if placing the stripped down frame in a vice with enough pressure to accidently cause this damage would be something that would /could be done in the course of servicing this pistol. And with the crack starting all the way up at the end of the groove for the slide (and the conspicuous lack of expected marks from either a vice or shop press) I can't say I believe pressure on the side caused this damage. It just doesn't look or feel right to me, so I'm one vote for force along the long axis of the pistol causing this.

And Yes, it is an interesting exercise (but at this point it's only a series of wild guesses!).

Attached Images

Cracked.jpg (71.7 KB, 39 views)

I'VE SEEN THIS BEFORE. ON THE ALLOY FRAME 9MM. IT CAME FROM A VERY WORN OUT RECOIL SPRING. IT TOOK APP 25K ROUNDS. THE CRACKS APPEARED ALMOST EXACTLY THE SAME. BEING THAT'S A SS 45 FRAME IT WOULD HAVE TO HAVE BEEN A VERY HIGH AMOUNT OF ROUNDS OR VERY HIGH PRESSURE ROUNDS. THE CONVERSION CALIBERS LISTED ABOVE COULD EASILY HAVE CAUSED THIS DAMAGE IF THE STANDARD RECOIL SPRING HAD BEEN USED. JP

Crack propagation typically does not travel thru a hole ( in this case, cutouts) since the internal stresses to the metal causing the failure cracking are relieved at the cutout as these internal stresses “travel” around the cutout vice thru it and are therefore distributed.

This is damage caused by some sort of mishandling.

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"Your other right........."

I don't understand what you mean. Why would someone replace the barrel just to shoot 45 Super? I shoot them in mine with an unaltered barrel.

.

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Waiting for the break of day

I meant if someone experienced a problem shooting Super (and damaged the barrel, more than the frame) and then replaced the barrel to sell the gun.

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Ret LE Firearms inst & armorer

Normally I would agree with you, but in this case the hole for the slide stop shaft is not "normal". It has been counter-bored leaving a thin shelf of metal for the inner part of the hole with a right angle at the base of the shoulder cut, and it has the groove for the slide cut through the top curve also leaving tiny right angle cuts - and angles are weak points in any material.

The missing metal in the slide stop hole and the odd gouges/marks in the bead blasted finish especially under where the grip should be and at the sear pin hole make me think this is some attempted gunsmithing mishap using excessive force against the frame, maybe to try and free up a locked up slide or similar condition.