I searched but figured I'd find an answer here. I have a pII and I have replaced this pin three times in the last 6 months. It breaks in half. I use heavy loads but not that heavy. 255 swc 5.3 unique 850... no signs of battering at all but wondered why this keeps happening.
Have you examined the Main Spring Housing Pin Retainer? Perhaps the point is abnormally sharp.
Breaking the Main Spring Housing Pin is really quite remarkable. The load on the pin, transferred through the retainer, is the 23 pounds of pressure applied by the Main Spring via the Main Spring Housing Pin Retainer.
I'm not able to see how recoil would affect the force applied to the Main Spring Housing Pin. The frame grooves and Main Spring Housing ribs would absorb the x-axis (rearward) component of the recoil impulse. The y-axis (vertical) component of the recoil is really small
Where are you getting the pins that break? Is the original one the original Ed Brown piece?
That's just plain weird. If the pin is getting enough of a pounding to break, how does the hammer strut survive?
Are there any odd, vertical scratches at the top corner of the hammer's face?
The mating surfaces of both the MSH pin and the MSH pin retainer are supposed to have a 1/16" radius. Beware of gun show MSH pins.
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Are there any odd, vertical scratches at the top corner of the hammer's
face?
Spyros, the only load the hammer strut sees is the same as the Main Spring Housing Pin: 23 pounds, more or less. The hammer is stopped by the grip safety before the spring stacks solid.
Come to think of it, if the spring were somehow stacking, then you would get a higher load; but, the hammer wouldn't be stopped by the grip safety, and that would be obvious when decocking.
Walt, in an in-spec 1911, I'm 100% certain that you're right. But if the strut is a little longer, or the strut pin hole on the hammer a little lower, or the hammer's face a little too long/tall?
Still, even with such a scenario, I would expect the strut to break first.
The first pin was the original from LB. The next two were Cylinder and slide 2 pack from Midway... I have on order two Wilsons... Figured I'd try those... I will check later the retainer radius... And the strut... no marks on the hammer... To tell the truth if I used the original grips the breakage would not be a problem, they would hold the pins in. Don't tell Less I have been using a hogue rubber fingered grip and these are cut out over the pin holes. During my last shoot when I got back to the pits one side fell out and the other half was just barley in... On my next leg I Prayed it would not fall out, duct tape works miracles hahahaha... Boy did I get a ribbing about my expensive gun running on DT...
Thanks for the responses.
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Walt, in an in-spec 1911, I'm 100% certain that you're right. But if the
strut is a little longer, or the strut pin hole on the hammer a little lower,
or the hammer's face a little too long/tall?
Still, even with such a scenario, I would expect the strut to break first.
We are in complete agreement. The way to detect such anomalies is to see if the hammer stops on the grip safety, or stops before reaching the grip safety.
The strut is not desiged to "stop" the hammer .
Perhaps the mainspring has a extra coil or two?
I'd give the Baer folks a call.
Ah, but what stops the hammer of this particular pistol? The grip safety, or the strut?
The grip safety stops the hammer and when bottomed out has no additional stress on the strut... I could take a pin and deepen the retaining spring grove a bit... This is where they break... maybe smooth over the retaining spring a bit?
Colt's been making pins & pin retainers for about 100 years. Why mess around with what appears to be defective merchandise?
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Colt's been making pins & pin retainers for about 100 years. Why mess
around with what appears to be defective merchandise?
Are you saying LB installs defective pins and cylinder and slide pins are defective? Do you think the MSH istelf is defective? I will order colt pins if you think this is the answer.
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I will order colt pins if you think this is the answer.
The Big People on this thread are a lot smarter than me.
But my magic 8 Ball suggests it ain't the "pins" that's the problem
Something is out of spec
What it is, I haven't a clue.
If the pistol is under warranty, I'd let the fine folks a LB have a look.
If not, I'd replace the MSH (along with all the MSH internals) first
If that didn't do it, and it's not under warranty, I'd let a genuine 1911 pro 'smith determine what's out of spec.
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Are you saying LB installs defective pins and cylinder and slide pins are
defective?
Not me. You're the one who said your LB and C&S pins were breaking.
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Do you think the MSH istelf is defective?
No, not as long as the pin will slip in easily with the cap, mainspring and retainer removed.
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I will order colt pins if you think this is the answer.
I always order 1911 parts from Colt - unless Colt doesn't offer it - but can give no guarantee they'll solve your problem. That's because your problem is so extraordinarily rare.
If there's any lingering doubt that your hammer strut might be too long, here's how to tell:
Remember too, as Walt mentioned, that the grip safety (and not the strut) must limit the hammer's overcocking motion when it (the grip safety) is depressed (or Off). In other words, if you rotate the hammer back and overcock it as much as possible, the hammer spur alone should fully depress the grip safety.
As I recommended earlier; you really should give the Baer folks a call.
Breaking any, much less multiple, MSH retaining pins is not normal wear or maintenance.
Something's out of spec.
I'm not sure why the op has not put up a photo or two because I can't even tell which pin he is talking about. I'm thinking that it might be the tiny pin at the top of the MSH, not the large one that keeps the MSH in the gun. In case we are actually referring to the tiny upper retaining pin, I would think the strut is too short, causing the cup to slam against the retaining pin each time the hammer is dropped. So in either case, it would be more than simple to observe a problem. Strut too short: hammer is loose when it is down, mainspring retaining pin takes a beating. Strut too long: main spring is stacking, MSH retaining pin gets stressed. I have never seen either of these pins broken and I don't carry extra ones in my emergency kit.
Some additional thought prompted by Cap's and Rick's posts made a little light go on in my head. If the pin hole at the bottom of the MSH was too big (or if the pin OD was too small), it would create too much additional space for the pin. That too much additional space might allow the mainspring/pin retainer to bend the pin too much - and might lead to its breaking - especially if the radius at the bottom of the pin retainer was too small - or if the radius at the center of the pin was too big. Maybe.
Pin hole in MSH ID = 0.160 + 0.002 inch
Pin OD = 0.156 - 0.002 inch
The housing is a bit out of square and allowed the grip safety to just barley touch it in one small area. The housing is a bit longer on one side. Piece of junk. I will call LB tonight but will take a bit off that area on the housing so I can shoot this weekend.
The strut is in spec, the pin holes are fine, the grip safety is fine ( I switched it out with another I have, colored the area and it left the same marks), just my eyes didn't catch this rub mark on the first take down on this part...
Sorry about the picture but the housing has a rub mark that you can't see in the picture it marries up with the other rub marks. I will remove some material off the area on the housing. I need the gun running this weekend. If anything I see a new housing due me.
Thanks again guys and sorry about not seeing this sooner.
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The housing is a bit out of square and allowed the grip safety to just
barely touch it in one small area.
OK, so the bottom of the grip safety was rubbing on the top of the MSH. That might interfere with the smooth on-off operation of the grip safety. And while that rubbing contact would place a little downward force on the MSH, could that downward force be enough break the MSH pin? And break it in the middle??
I'd keep the duct tape handy for your weekend shoot.
LOL! I am a retired builder, duct tape has saved many a day!
Great thread and good info. I too have had a MSH pin snap in half. I replaced it and haven't had any problems...yet. The TRS is second hand so its history unknown. Looks like I have some homework to do!
Keep in mind that the pin retainer (the pointy one in the very bottom of the MSH) should only limit the MSH pin by dropping into the groove. It should not intrude into the bore enough to contact the pins groove at the minor diameter. If it pokes out too much and the point hits the groove it will stress the pin and lever the pin at the groove every time the gun is fired.
I would modify the retainer so it only blocks lateral movement of the MSH pin but does not contact the pin at the center of the groove.
I now have 300 round with the filing I have done and no breaks so far...Do have a few spare pins...