My XDM 9mm 5.25 Comp-Problem

Cherokee

Medina, Ohio
I really like my XDM 9mm 5.25 comp pistols; shoots great and it is 100% reliable - but: there is a hair-line crack in the breach face running downward from the firing pin hole to the lower portion of the slide cutout for the ejector. This is after 5200 rounds. This is the replacement slide for the original, which did the same thing after 7300 rounds. Yes, that is two slide with breach face cracks in 12,500 total rounds. I had the same thing happen on an identical XDM that I have, except it took 26,000 rounds in that gun to go through two slide. SA has always replaced the slides without question and free of any cost to me. Is it the ammo you might ask; I don't think so. Its Lee 120 TC over 6.1 gr of HS6 @ 1.055" OAL. Chronographs at 1180 fps so it is a service level load but not +P. I'm inclined to let SA keep replacing the slides because I like the platform so much. Any thoughts you want to share ?
 

fiver

Well-Known Member
dang.
this is the first I have heard about them having an issue, but if they just replace them no questions I would imagine they know about the problem.
 
F

freebullet

Guest
We have/had a nice cross section of xd pistols. Never an issue. I think the 4"9 has over 30k lee125 2r through it. We fired 1780 Lee 452 200 through the 45 in one hot afternoon, still showed as new when I sold it.

Shocked you had that happen, glad to hear they take care of it. I'm wondering if you have a minor out of battery situation. Extremely worn recoil spring, something has to be a cause, huh?
Thanks for sharing your experience with it.
 

Winelover

North Central Arkansas
I guess I should keep an eye on my 9 mm XD Mod. 2 Compact. Don't nearly have that many rounds through it, yet. It's a good shooter and both the wife and I are pleased with it.
 

Cherokee

Medina, Ohio
I have an XDM 45 ACP 5.25 comp with 12K rounds through it and it is fine. Also, my XD 9mm sub-compact, my EDC, is fine, about 2K rounds through it. As you can see, I like the platform and do not want to switch. Here is a pic.
 

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Winelover

North Central Arkansas
I like it too, although it's a bit large for concealed carry. Nice trigger and sights..............Cindy, likes the red pipe type front. I'll keep and eye peeled, nonetheless. I have @ 2000 cast rounds through it, without a hiccup.
 

Cherokee

Medina, Ohio
SA agreed a repair was needed after seeing the above pic and sent me a prepaid return which will go out Monday.
 

Pistolero

Well-Known Member
The crack is started by the sharp inside corner of the slide, and the FP hole is acting as the
"stop drill", which will almost certainly prevent the crack from further propogation. I would
want to understand what the heck is going on here. Without looking over the gun, it isn't
clear to me that there should be any high tensile stresses in that particular inside corner.

They need a slight radius at that corner, even a .025 would help a lot. If it is a sharp internal
corner, it is a huge stress concentrator at that location. But, my first glance, without seeing
the whole gun and understanding the loading better, makes me think that there shouldn't be
much stress there to begin with, so, even concentrated, I am a bit surprised.

Clearly a design/manufacturing issue if two have done it. No fluke.

Bill
 

Cherokee

Medina, Ohio
Bill: Thanks for the thoughts. I hadn't thought of the focused stress on the 90* cut. Actually, this is 4 slides in two different XDM 5.25 9's.
This is the breech face so it gets the full pressure from the cartridge ignition but is spread round 360* on the breech face. The cartridge rim extends to just shy of the ejector cut so there is no mass beyond it like most of the breech face. But there is the extractor cut that on the other side of the breech and no crack develops there. I'm no engineer but I'm convinced its a design/mfg issue SA does not want to admit.
David
 

Cherokee

Medina, Ohio
fiver: I wondered about that too, but it seems so basic for it to be straight back that I can't imagine they got that wrong, but...
 

Pistolero

Well-Known Member
Clearly there is very high stress, but without handling one and looking it over for
a while, it is not at all clear why there should be high stress there. Another possiblity
is that they heat treat the slide and lock in some serious stresses from cooling,
and they eventually equalize by cracking.

Clearly their problem, and a bad design. If I was on the team, I would immediately
change the slides to have a .020 to .030 radius in that corner, cheap and easy, good chance
of solving it without fully grasping exactly why it is happening. May require some other
changes to fit, not sure. No doable after the fact.

Inside corners in anything significantly stressed should never be tight, sharp radius. No
benefit in most cases other than easy to run a sharp cornered mill cutter in there rather
than get one ground with a tiny radius, and use it for the finish cut.

I spent a career with people bringing stuff like this (not guns) to me and paying me
to "make it stop". Often I had a good idea right off the bat, at least after the first
decade or so. But long distance, not handing the pieces and looking at them for
quite a while, nothing jumps out. In many cases, the pieces sat on the desk for
a few days, while I studied materials, loading conditions and started on computer
models. Sometimes it just jumped out, but often took a computer model to show
what was really happening. My bet is that they don't have any of that kind of
engineering in house, not common in smaller companies.

I designed, patented and sold a replacement recoil spring plug for Officers ACPs, the
originals broke, and we paid extra for a cutter with 0.010 radius to be specially ground
to avoid this in our interior corner to the flange, highly stressed area. Also, I used
a very strong alloy. Never had one fail, and we have a lifetime guarantee. Still have
a few if anyone still has an Officers ACP with original spring plug. At one point they
asked us for a quote for supplying them, but they wouldn't/couldn't pay what we needed, even
if we upped production quantities masisvely and changed to more efficient methods, so it went nowhere,
They totally redesigned the system for current models.


Bill
 

Pistolero

Well-Known Member
Good. Of the various "plastic fantastic" new gen pistols out there the only two
that have appealed to me are the S&W M&P (I got the .45) and the XD, my brother
has one, and I like it pretty well, although the extractor seems a bit mechanically
odd, but certainly works. One of the better, more ergonomic designs.....well other than the slide
cracking issue.

Bill
 

KeithB

Resident Half Fast Machinist
Gotta agree with Bill. Two possible causes, could be either or both. Mechanical design - high stress from poor design, which includes everything from load calculations to manufacturing execution, i.e. sharp inner corners, etc. Thermal - poor heat treating that leaves residual stresses, especially combined with sharp corners as stress risers.

poor design + poor heat treating + fatigue from cyclic use = return gun to factory?
 

Brad

Benevolent Overlord and site owner
Staff member
One is a fluke, two or more is a pattern.
Design flaw somewhere.
 

fiver

Well-Known Member
I know there are a lot of these guns out there.
I'm wondering if there are a bunch more and the owners just haven't seen this, or if it just pops up in a few guns here and there.
 

Pistolero

Well-Known Member
My guess is that it is based on number of rounds fired. A WHOLE lot of folks shoot about
20-50 rds a year, so will never see this in their lifetime.

My bet is that the number of shooters who EVER shoot 10,000 rds is like 2% or so, maybe
even less. A lot of guns are on pure standby service. The owner puts two mags (or less) thru
it and put it away, never to shoot it again unless they get an intruder.

Bill
 
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Brad

Benevolent Overlord and site owner
Staff member
I agree Bill.
Our club has 2K members and I bet that 5% fire 95% of the rounds fired annually.