Slide crack or dent?

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cherryriver

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This one's been keeping me awake nights for a while, now.
This is the left side of my Combat Commander, the one that was my first gun. There's a mark here just behind the scallop that sure looks to me like a crack.
At the limits of my close-up photography skills, you can see two marks, a shorter curvy one that is what I first saw, and then that second, longer one.
The loopy squiggle atop the one mark that looks like an old television antenna really is there; it isn't just a piece of fuzz.
There is a shade of a hint of a mark across the bottom of the slide there, and it is exactly in line with the start of the dustcover part of the slide.
There's no such anything on the starboard side.
I fretted over this last year on a forum and learned there's no realistic way to weld up a forged slide like this. I did make a half-hearted attempt to find a replacement but without success.
If this was another gun, and I have other Commanders, I would just set it aside or throw on any old slide. But this one is the most prized possession of any, and I'd really rather see about keeping it going.
Since I've already seen a Para slide break in this general vicinity, I take it seriously. Still, once a local smith looked at the curvy mark and said he thought it was a dent, not a crack, I went on shooting it, about another 1000-1300 rounds. (The thing probably has well over 50K lifetime, and yes, I didn't know back in my youth that you had to change recoil springs every so often.)
I can't make up my mind whether the extra shooting changed it, but I think there's a chance it did.
I think I'm appealing to those who've seen a fair number of slide breaks over the years and might recognize it for such.
Since I put a Brown barrel and some other stuff in it a couple of years ago when I first started shooting practical matches, it shoots and runs absolutely wonderfully, far better than it ever did back in 1973, and better than the highly-customized replacement I got last year to get me to stop shooting this one.
Thanks
Bill
ComCom slide crack 9-06.jpg
 
All I can say is that is where they crack when they do crack. That little line across the bottom edge sure looks bad, though. I would not neglect it, I would get it checked out. EGW has a good reputation for welding on guns, I don't see why it could not be fixed.
http://www.egw-guns.com/
 
That's a stress crack (actully they both are). The Bubba"garage" fix was to drill a small hole at the end of the crack to stop it from "running"..and it does work, but is uglier than my Aunt Betty (and that's a whole bunch of ugly).

Finding someone to weld up a cracked slide is getting pretty hard...most don't want the liability.

Wish i could see where it was on the slide...common is where the slide goes from thin sided wall to solid (near the breech face). may as well take a hard look at the frame as well, these things often come in pairs.
 
Looks like a crack to me, the location and the mark across the bottom are the things that seal the deal for me.

I would stop drill it and shoot it until it died. STI makes really nice slides, about $175 bald, figure on $325ish installed with sights and a quicky blueing.......
 
I'm pretty sure I can weld that and clean it up, then re-heat treat it.. You'll have to get it reblued.

I've fixed magazines, slides, even done a couple of 1911 frames, and a cracked AR lower once that's still shooting 10 years later.. I'll need to check what the alloy is (should be 4140) and match it.

Obviously I can't be sure without looking at it.

It shouldn't show much if at all. If there's any kind of deformation beyond cracking it calls for a judgement call on whether to weld it or toss it. But if it's shooting now, it should be fixable.

I get cracked blades in all the time--right at the tang from someone beating too hard and creating a stress riser.
 
The slide is blue carbon. The lighting I used to try to emphasize the mark/crack washed out the colors.
I'm good with the welding concept in general. I've had a little training and experience, and so have been exposed to some impossibly good welders. I know an aircraft-certified/tech college instructor in southeast Wisconsin who does aluminum repairs that are inhumanly perfect. I'd let him weld anything he cared to.
The thing is, I've been told, and I believe this includes the esteemed Mr. Tuner, is that forged parts that require straightness, like a slide, are not such good candidates for weld repairs.
On the other hand, the crack is still quite small and so may be more repairable than a larger one.
It is shooting extremely well right now. Blows me away, this old, beat-up, former kid's gun running so perfect and true.
The real issue is the attachment thing- I guess I just don't want someone else's slide on my gun.
Any other gun in the safe, no big deal. This one, well, it's different.
Thanks
Bill
 
My FLG once squeeze-tightened a slide because the customer insisted on it after being told it was too hard and might crack. He did and it did, the little hangy-down part behind the safety notch. He welded it up, machined it back, and reblued. Shot and shoots fine.

It can be fixed.
 
Madmike needs metallurgy lessons ! Do not attempt to reheat treat the slide ! It would be a good idea to temper though , after welding at 400 F. A good TIG welder could do the job. I would assume 4140 as the steel so using the proper wire for that color difference after rebluing would be minimal.I would assume 416 for a stainless steel slide.That could be welded also. No one makes an aluminum slide that I know of and I have no idea which aluminum alloy they use for frames. BTW the S&W 'scandium' frames are an aluminum alloy with about 1/2 % of scandium.
 
Crack

That's an impact-induced stress crack that will very likely continue unless stopped. Welding is possible...but unless the welder is very good, warpage will probably result. If it were mine, and as well-used as you say, I'd check-drill it. Use a punch...lightly.. at the terminus of the crack. That'll provide a dimple for the drill, and it'll compress the grain structure a little in the process.
Use a small drill bit...the smaller, the better...Grind a shallow "V" along the length of the crack...and put just a dab of weld in it. Torch welding may be better than TiG if the welder knows his stuff. It's less invasive.
It would help to know exactly what the steel alloy is.

It will also help to soften the shock on the area. I'm not a fan of shock buffs, especially in guns shorter than 5-inch...but sometimes it's not a bad idea. Chuck the recoil spring guide rod up in a lathe and face the rear of the flange off to about .060 inch thick. Face the butt-end of the rod a like amount, and order a set of Hiett Technologies .090 buffs. They're the thinnest buffs available, and...along with the reduction in flange thickness will offer the least amount of loss in slide travel...as opposed to dropping in a standard buff of about .110-.120 inch thick.

The other option is to simply buy another slide and have a smith check everything out to make sure the specs are compatible.
 
You will have to retreat the slide because the welded section will be completely normalized and the rest won't. This leads to differential states of the metal, both face-centered and body-centered cubic, which can cause additional stress and warping, not to mention uneven wear of material and uneven blueing.

http://www.findarticles.com/p/articles/mi_m0BTT/is_154_25/ai_77824399 Please see here.

It will be hardened in oil between 1525 to 1625 F and tempered at 500 F for about 3 hours.

I can't fathom why anyone would think a pistol slide is not heat-treated, but I would respectfully suggest anyone offering such needs the metallurgy lessons.

The aluminum was in reference to AR receivers and the occasional aluminum Govt Model frame.

Mike (Who after forging blades and fixing guns for 23 years knows a modest amount about the subject of heat treating steels.)
 
Metallurgy

Defers to the metallurgist...but one point:

>I can't fathom why anyone would think a pistol slide is not heat-treated, but I would respectfully suggest anyone offering such needs the metallurgy lessons.<
*********

On early 1911s, neither the slides nor the frames were hardened. WW2 USGI slides were spot-hardened in key areas, but the rest of the slide was dead soft. In 1935 or thereabouts, a hardened steel insert was added to the breechface to eliminate the peening and deformation on the face, and around the firing pin port, that resulted from the case being slammed back against it when the pistol was fired. This was designated as the "Recoil Face." This practice continued until about 1947, when Colt began heat-treating entire slides...for both military replacement slides and on commercial pistols. If you look closely at a WW2 USGI contract slide, you can see the insert.
 
Certainly. The early Colts were a much lower alloy of steel. I'm not sure which, but I would guess a simple carbon with possibly some manganese, not the rich alloys of today. Also, heat treating was only understood for hardening at that point, not for the variety of results it could yield. There was also the additional cost involved.

On jig-bent AK receivers, one can also selectively treat the pin holes--the high wear area--with a torch and a squirt bottle of oil. It's not as refined or elegant as a full soak at temperature in an inert atmosphere, but it will work adequately.
 
My ~ 1970 Browning Challenger has the back of the barrel and breech face flame hardened as these are the impact areas. I don't know the steel but you can take a simple 1045 and flame or induction harden the surface.What you do is all a matter of use, steel, manufacturing process,heat treating process. There are lots of choices......500 F will temper but will not anneal .To anneal you need at least 1500 F !!...."check drill" This introduces the subject of Fracture Mechanics. Simply put, the propagation of a crack is inversly proportional to the radius of the crack. Increasing the radius can then stop propagation of the crack !
 
Tuner says,

That's an impact-induced stress crack that will very likely continue unless stopped. Welding is possible...but unless the welder is very good, warpage will probably result. If it were mine, and as well-used as you say, I'd check-drill it. Use a punch...lightly.. at the terminus of the crack. That'll provide a dimple for the drill, and it'll compress the grain structure a little in the process.
I got the same advice here from Tuner with respect to a similar problem. Of course my crack was in the dustcover, which some might say is largely a useless appendage anyway. :) (Kidding, kidding -- I think?)

Anyway, during the month since I followed Tuner's advice and added a 1/16" hole to my dear M1911 she has had the time to fire only about 500 rounds, but she has shown no evidence of any further cracking.

Tuner reminds me of a stockbroker's ad on TV -- "When the Tuner talks, people listen!"

Hold 'em and squeeze 'em.
 
Stop-drilling is used as a field expedient repair for airframe damage, too.

It's also why leather sheaths cut with a belt loop have holes at the ends of the slits.

mete, you're correct (but pedantic) on annealing temperature. However, 500 F for three hours on most non-stainless alloys will relieve enough stress, especially around a crack, that applying heat for welding shouldn't cause additional stress cracks, which is possible with a treated piece. "Anneal" is the colloquial phrase for people who are only hazy on the difference between harden and temper in the first place.

Also, it is possible to fully spheroidize most carbon steels at 500-600F, given a long enough soak.
 
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