Springfield Mainspring Housing Oddity

I was doing some late night cleaning in preparation for next weekend's service pistol matche and noticed when I disassembled my RO that the mainspring and cap were sticking out the top of the housing.

Cannibalizing a cap retaining pin from another 1911 and inserting it in the housing on top of the cap results in the hammer loosely falling into half-cock.

I've cannibalized an entire mainspring housing group from another 1911 for the match and everything functions normally. But I'm trying to figure out what I broke in my original mainspring housing group and how to fix it.

Sounds like you have an older ILS mainspring housing there.

Neither of my RO mainspring housing ever seemed to have had a retaining pin.

weber1b wrote:Neither of my RO mainspring housing ever seemed to have had a retaining pin.

Don’t think that’s possible.
An ILS has one opposite the lock.
A std MSH has a single one offset.

james r chapman wrote:

weber1b wrote:Neither of my RO mainspring housing ever seemed to have had a retaining pin.

Don’t think that’s possible.
An ILS has one opposite the lock.
A std MSH has a single one offset.

Please show a pic

My ILS mainspring housing came with no retainer pin.
The disassembly instructions were to engage the lock before removing the housing.

STEVE SAMELAK wrote:My ILS mainspring housing came with no retainer pin.
The disassembly instructions were to engage the lock before removing the housing.

I don't know exactly what ILS is but I'm guessing I have it.  

I don't however have anything to disengage the lock, if that's what this additional 2-tiny hole bit in the back of the housing is.  

This housing is different from the others on the 3 1911s I own.  In addition to the business listed above it has an additional hole in the top near where the guts go in.

Will send a picture when I am able, hopefully at lunch.

STEVE SAMELAK wrote:My ILS mainspring housing came with no retainer pin.
The disassembly instructions were to engage the lock before removing the housing.

Which I never did. Who ever thought of actually reading instructions. A little bit of a pain putting back together but not a major deal. I have since replaced them with arched housing anyway.

adminbot1911 wrote:

STEVE SAMELAK wrote:My ILS mainspring housing came with no retainer pin.
The disassembly instructions were to engage the lock before removing the housing.

I don't know exactly what ILS is but I'm guessing I have it.  

I don't however have anything to disengage the lock, if that's what this additional 2-tiny hole bit in the back of the housing is.  

Yep, that's it. Integrated Locking System or some name like that. The gun comes with a little key to engage/disengage it, which you can do only when the spring is cocked. When ILS is engaged, the spring becomes trapped and cannot extend to push the strut.

Springfield doesn't ship it any longer. You can swap out the whole assembly but there are some fitting quirks, especially for the SA compacts. I phoned Smith and Alexander and they set me up with exactly what was needed.

Okay, great.  And by "great" I mean "not great" since my trigger weight is below 4 pounds now. 

On Brownell's ordering a whole new MSH and internals.  And a couple of sear springs I can fuss around with.  This MSH group is going in the parts bin.  Hopefully the lot will arrive by Friday.

Semi related.  Which MSH has the most aggressive checkering, I sweat on my palm a bit and I like sharp checkering so it doesn't move at all.

adminbot1911 wrote:Semi related.  Which MSH has the most aggressive checkering, I sweat on my palm a bit and I like sharp checkering so it doesn't move at all.

There might be others but I love my Smith and Alexander. Arched-back.

-TT- wrote:

adminbot1911 wrote:Semi related.  Which MSH has the most aggressive checkering, I sweat on my palm a bit and I like sharp checkering so it doesn't move at all.

There might be others but I love my Smith and Alexander. Arched-back.

You read my mind.  This is already in my shopping cart.  

Cheers

At lunch I dug through my old cases including the Springfield one that came with the RO.  Sure enough, there was a "key" in there that would turn, indexing the locking mechanism in the housing.

I'm still ordering the Smith and Alexander parts and internals.  But if I wanted to reset everything back to normal, how does this mess go back together in the stock SA MSH?

There's nothing too special about the ILS MSH except for the locking mechanism and the way it fits into the special plunger. You'll need to get the ILS free from both it and the mainspring, which in your case sounds like it may need some fiddling.

Assuming you have the MSH out of the pistol, try using a punch to press down on the plunger while you twist the ILS. You may need to bump it a bit, up and down. Once it's unlocked, dealing with the MSH is pretty much like normal.

Note, the ILS mainspring and plunger are different from stock (shorter and longer, respectively I believe). Don't try to mix and match them with your new parts.

Right, good advice, these parts are staying together, either in my parts box or in the trash can so the urge to mix them up won't be there any more.

I guess my question is that now that it's unlocked, how do I get it so the spring and plunger are captured correctly again?  It was unlocked when I removed it, shouldn't it be locked now? Does it lock above the plunger or in the beveled groove?  Doesn't that keep the hammer from coming back at all?  I'm pretty mechanically minded but I can't figure out the purpose of this "lock" or how it worked before but doesn't work now.

Clamp it in a padded vise.
Assemble as would come natural.
Depress plunger until you can insert the little bent rod that came with the gun and had no apparent reason for being.  It inserts from the checkered side of the MSH.
It is now ready to be pawned off on someone you don't care for.

HA! Classic.

The step after "insert little bent rod that had no apparent reason for being" is "reengage lock" correct?  Unless I REALLY don't like them and I want that sharp plunger flying out at their face when they remove the bent rod

The bent rod is the disassembly keeper and stays in place until you reassemble the pistol.
Once the MSH is in the frame you cock the hammer & remove the bent pin.
You're supposed to use the pin for stripping....cock the hammer all the way back & insert the pin, then release the hammer which now has no spring tension on it. 

The lock assembly is not used for stripping the frame or reassembly...just the bent pin

Okay.  Now all the dots are connected and I understand the purpose of everything.  Thanks for the patience.

What a stupid design.

In the name of safety they created something for me to put an eye out with.

I'm sure they meant well.  

Honestly, I guess I forgot about the locking pin. IIRC, I stuck a pin punch in there, yanked it out later and threw the rest in the trash.

STEVE SAMELAK wrote:In the name of safety they created something for me to put an eye out with.

A case of solving a problem that did not previously exist.

Smith and Alexander arched MSH, stainless internals, and a crisp 4.5 lbs trigger weight. All is right in the world again.