Springs binding in my Shorty 45

So I've got this Shorty 45 mk.2 with the standard fare 4513 nested recoil springs in it (pn10866 & 10867) specified & ordered from S&W. I observe about an 1/8" difference is slide travel with the springs out.

Here's a photo to illustrate. The slide bottoms out at the red line with the springs installed. Without the springs it bottoms out where you see it in the picture.


Now having been weaned on 1911's many moons ago, I know that spring bind/stacking is often fatal to a 1911. I'm not sure what the effect might be on a 3rd gen but I can't imagine it's a good thing and I know I bloody well don't like it. The only other gun I have that had this problem was my 4516-1 with an aftermarket extra power spring and that was resolved.

I had just fit a set of 2006 night sights and some factory low profile controls with the intent of putting this piece to more use.
I was very pleased with the results until I noted the spring stacking issue.


Anyway, I would like to correct this but first I want to make sure I'm not missing the boat on something or concerning myself with something that's a non-problem. Is there a special set of springs for the Shorty's I'm not aware of? I'm also curious if any other Shorty 45 owners have experienced this or could perhaps check their guns for stacking.

Cheers
Bill

Hi BMCM,

I will admit ignorance of the binding/stacking issue you are referring to. Well.........I understand how a binding spring could present problems, but what is "stacking"? And why is it problematic?

My Shorty 45 MKII is in storage, so I will go check it this weekend for you and let you know if the results mirror your experience.

I did try what you asked with my 4566 and my 4513TSW. Both slides went back a little bit further, approximately the amount you illustrated, without the springs and guide rods installed.

For myself and perhaps some other shooters who do not understand why this is a problem, would you please explain it to us. I always learn from your posts and this one appears to be another lesson to take advantage of. Regards 18DAI

Bill's post and 18's reply raised a three point question in my mind that for me, admittedly, doesn't have an answer:

A. Was the recoil spring(s) intended to be the limiter of slide travel at coil bind?

B. Is there some other positive, mechanical limiter of slide movement?

C. Was there some intentional designed balance between spring resistance and charge pressure so that with "proper" loads the slide shouldn't reach the physical limit of travel?

Inquiring minds want to know.

John?

Lots of precision measuring & ciphering of numbers going on at my bench. more to follow later

Cheers
Bill

The base of the guide rod, spring and inner face of the dust cover takes all of the brunt of a hot load and only thing that stops the travel of slide or you would have macerated surfaces on the frame and slide so if you remove such then the slide will smash the frame this is perfectly normal and as designed

Ok, I did a bunch of measuring today comparing my Shorty with 3 different 4513 uppers and I'm confident I've identified the cause of this issue.

To start with I'll define a few things how I view them regarding recoil springs so were all on the same page?

1. Spring stacking or bind; This is when a recoil spring is completely compressed.

2. Spring stack height; This is how tall/long the spring is when completely compressed. Quick & dirty way to determine this is multiply the wire diameter by the number of coils.

3. Installed Space; The room available for the spring to occupy when the slide is fully forward in battery at rest.

4. Compressed Space; This is the space available for the spring to occupy with the slide fully retracted with the spring tunnel resting solidly against the the mechanical stop in the frame. Where we run into trouble is when the spring's stack height is greater than this space.

So why is spring stacking or bind a bad thing?

Well, here are my thoughts; I think for the most part this ought to be common sense. A spring's purpose is to store & release energy. In this case, when the spring has stacked solid it's in effect full. Having reached it's max capacity for stored energy any overflow is transferred into the surrounding structure.

So what happens then? When your recoil spring looks like this before the slide has reached it's mechanical limit.


This is the slide's mechanical limiter. All that impact force that should normally be going here.

And here when the slide bottoms out on the frame.


Is now being directed into the front inside face of the slide's spring tunnel and into the frame through the flange on the guiderod here.


In short, when the spring stacks solid before the slide reaches the mechanical limit of it's rearward travel, things will get battered that aren't supposed to be. Repeated stacking also damages and accelerates spring weakening.

I think there are two primary considerations for selecting a recoil spring.

1. Does it fit the gun? I contend that a spring that stacks before the slide reached it's mechanical limit does NOT fit.

and

2. Is it the proper weight? A spring that's too weak will wind up with slide battering the frame. A spring that too strong will cause battering of the locking lugs both on the barrel and slide as well as the slide stop cross pin and the mating cam on the barrel underside as the slide is flung forcefully back into battery. Either extreme also comes with a host of functioning problems in addition to the battering.

I want my spring to fit the gun properly and be of sufficient strength to halt the slide at or near it's mechanical limit and send it back into battery without any stacking or undue battering of any components.

We trust the factory engineers to make these selections for us and assume the OEM replacement parts are "good 2 go" and 99 percent of the they are.

I'll just blame the beancounters for the remaining 1 percent.

Now taking a look at these nested springs. These springs (108660000 & 108670000) were/are used in a bunch of different guns. All the compact 40's, and all the compact 45's except for the 4516-1. Plus the Shorty & the Recon45 and I assume the Shorty 40 as well. That's maybe 14 different models by my count. Maybe when they were building the Shorty's the beancounters just made 'em use whatever was in the bin

I have no stacking issues with these springs in any other gun it's only the Shorty where there's a problem.

On to the spring measurements.

pn 108660000 outer 0.37wire x 22 coils, stacks at .814"
pn 108670000 Inner 0.32wire x 25 coils, stacks at .800"
ISMI #18 flatwire 0.26flatwire x 31 coils, stacks at .806"

Shorty 45 mk2
Installed space 2.817"
Compressed space .774"

4513TSW
Installed space 2.876"
Compressed space .941"

As you can see, the 4513 has ample compressed space for any of those springs. The Shorty however comes up a little uh short.

And the source of those differences between the two gun is this.
Here's the front of the spring tunnel on a 4513, note the thickness of the front face, it's 0.68" thick.

And here's the same view of a Shorty45 slide, note the thickness here, it's over double the 4513's at .138"


Well there it is. You know I think there will come a day when those nested springs we use in so many of our favorite guns go the way of the dinosaur just like the factory 4516-1 spring did.

I think I'll get to looking for an alternate part for my Shorty. For all the other guns, I've had superior results with the ISMI flatwire springs and I intend to keep using them.

I was kinda hoping an old retired S&W PC guy or engineer would chime in, I sure like to hear some insight from anyone who was working at the PC back in the day, Ah well. If anyone who has a Shorty, or anything else that runs on those nested springs for that matter, feels like measuring or checking your spring fitment I welcome your input.

Conversely, if/when I source a suitable replacement spring I'll post that info here. In the meantime, the Shorty goes back in the box

Cheers
Bill

Very interesting Bill, I follow this for the most part but I'm getting a little stuck in the weeds on some of it as well.

Since the Shorty45 has less compressed space it is unable to take Full advantage of the springs capability to absorb and release energy therefore it is more susceptible to slide /frame contact? Bind/stacking is a bad thing but in the Shorty45 the spring will never have a chance to completely bind? So is you goal with finding an alternate spring one that will function reliably, not bind and work up to or close to the compressed length?

The TSW is able to take Full advantage of the springs stack height however if not at proper weight it will be allowed to bind and also have potential for frame and slide contact? The goal here is to allow the spring to function without going beyond the stack height, close but not past?

Also, Is the spring tube on the Shorty45 thinner or thicker? Not sure I interpreted the dimensions correctly?

I wouldn't have noticed that the 457 uses the same spring set except that replacement springs have been backordered from S&W since July and I was Googling around looking for an alternate source. Just as a datapoint, it appears that the 457 stacks up approximately the same amount as shown in your photos.

My new to me 457 appears to have been fired very little, but it doesn't look like the flange has been hammered on - though it is pretty thin and a very light alloy. Doesn't look like it would take a lot of abuse. Could it be that this is not a problem unless the springs have gotten very very soft? Even then, would there be enough energy left in the slide to do any damage by the time the spring is fully compressed?

This does reinforce the need for regular spring replacement. If anyone knows of a source of springs, I'd appreciate a heads up. The 10866/7 set is backordered from S&W, Brownells and Midway. Wolff doesn't make this spring.

BTW, Bill, how did you ever find this problem? You need to get out more - go to the range - get a girlfriend or something. <G> Thanks for sharing, though. I always learn something from your posts.

03Fatboy said:

Since the Shorty45 has less compressed space it is unable to take Full advantage of the springs capability to absorb and release energy therefore it is more susceptible to slide /frame contact? Bind/stacking is a bad thing but in the Shorty45 the spring will never have a chance to completely bind? So is you goal with finding an alternate spring one that will function reliably, not bind and work up to or close to the compressed length?

Click to expand...

Slide to frame contact is not a bad thing so long as it's controlled. A soft landing on the frame by a properly sized spring of the correct weight for the loads is the goal. Nothing is getting battered and you get the all the advantages of the slides full range of travel. Cleaner ejection and easier to download. I gotta tell ya, clearing live rounds from the shorty is a major pain compared to any of my other 45s.
I think you may have misunderstood me a bit. The spring in the Shorty can do nothing but bind. There's simply not enough room in that gun for that spring. It may be the correct weight but It's simply too big.

03Fatboy said:

The TSW is able to take Full advantage of the springs stack height however if not at proper weight it will be allowed to bind and also have potential for frame and slide contact? The goal here is to allow the spring to function without going beyond the stack height, close but not past?

Click to expand...

Spring bind is when the spring is compressed to the point where it behaves not like a spring but like a solid piece of steel. When your spring stacks solid in there it's the same as having a solid steel tube on your guiderod instead of a spring. The stack height of the spring should always be less than the available compressed space in the gun this way it is physically impossible for the spring to bind. Again, slide to frame contact isn't bad. Uncontrolled slide to frame battering is. The two are not the same.

03Fatboy said:

Also, Is the spring tube on the Shorty45 thinner or thicker? Not sure I interpreted the dimensions correctly?

Click to expand...

The difference was the thickness of the front face of the spring tunnel where the guiderod protrudes, It's twice as thick on the Shorty tahn on the 4513. What I was attempting to illustrate Looking at the measurement differences in measurements between the two guns I posted the chief noteworthy thing is the Shorty has much less room than the 4513TSW to accommodate the exact same spring set.
And yet they both are 4513s

Hill_Country said:

I wouldn't have noticed that the 457 uses the same spring set except that replacement springs have been backordered from S&W since July and I was Googling around looking for an alternate source. Just as a datapoint, it appears that the 457 stacks up approximately the same amount as shown in your photos.

Click to expand...

Hill_Country said:

My new to me 457 appears to have been fired very little, but it doesn't look like the flange has been hammered on - though it is pretty thin and a very light alloy. Doesn't look like it would take a lot of abuse. Could it be that this is not a problem unless the springs have gotten very very soft? Even then, would there be enough energy left in the slide to do any damage by the time the spring is fully compressed?

Click to expand...

Hill_Country said:

This does reinforce the need for regular spring replacement. If anyone knows of a source of springs, I'd appreciate a heads up. The 10866/7 set is backordered from S&W, Brownells and Midway. Wolff doesn't make this spring.

Click to expand...

Yep, I've looked too, Out of stock everywhere. I'll find something that'll run in there. Fortunately the gun doesn't care what springs are inside, only that they fit and they work.

Hill_Country said:

BTW, Bill, how did you ever find this problem? You need to get out more - go to the range - get a girlfriend or something. <G> Thanks for sharing, though. I always learn something from your posts.

Click to expand...

After working out the replacement recoil spring for my 4516-1 I guess I look at springs a little more critically these days, especially since it seems our parts supplies are drying up and I intend to keep my toys running regardless.

I may try hunting up some springs to test out next week assuming I feel better. Seems I've caught a bug this week... Bleh.

Cheers
Bill

Hi, Bill!

I appreciate your analytical expedition into this matter and I did some checking on my own guns to see if I was experiencing the same phenomena as you.

The only pistol I have that sports the 6/7 S&W double spring is a pre-rail 4013TSW.
With or without springs the slide stops on the frame stop.

I also have a CS40. As you know it uses a single spring and yes it does the same as the 4013TSW. The slide stops on the frame stop.
However I also have both a 457 top end assy. and a late 4516-1 top end assy. that fit the CS40 frame. Both of these, as you know, use the S&W 6/7 double spring combination.
Both of these top ends exhibited approx. the same slide stop difference as shown in your picture with and without springs when installed on the CS40 frame indicating coil bind.

I suppose the ideal would be a spring/load combination which caused the slide to just kiss the frame on the backstroke before returning forward.
I also agree that finding a suitable flat spring would be preferable to cutting .050" off the inside face of the slide spring tunnel.

I'm with you. I don't like coil binding whether it's on guns, engine valves, suspensions, or anyplace a spring is installed to absorb and release energy. And in most cases, unlike engine valves, there is a positive stop in the system to keep the springs from bottoming.

John

BTW, Bill, when I look at the picture of the face of the spring tunnel on your Shorty, I think I see an annular groove running around the lower curvature of the guide rod hole at approx. the same depth as the 4513.
Is this a streak on my monitor or could there be a spacer somewhat like that on earlier 4516s except its purpose would be to pre-load the spring to increase its working pressure?

John

Hi John,

Glad you chimed in, I think your comments are spot on and
I couldn't agree more. Nothing good can come of coil bind.
Most any machine that depends on coil springs will grenade if the springs bind. As in, valve train springs bind and puking engine parts on the highway grenade. Luckily these pistols are somewhat forgiving in this regard in that once or twice usually won't destroy anything. Unless it's a 1911, once or twice can cause you to need plug & bushing or worse case a new slide.

Oh and not to worry, I have zero intention of machining the Shorty to fit a consumable part (spring).

Cheers
Bill

I see what you're looking at. I have that image here on the PC at stoopidhigh resolution. Zooming in on that area I see some tooling marks evident under the bead blasting that look like fine pitch screw thread. Evidently from whatever tool was used on that hole. I had another look at the slide too under the loupe and it's solid for sure. No spacer or bushing in there. It's not a streak on your monitor just a flaw in the image I think. That's just a real hard spot to get a good in focus shot, my camera keeps wanting to focus on other junk.

Cheers
Bill

JohnHL said:

BTW, Bill, when I look at the picture of the face of the spring tunnel on your Shorty, I think I see an annular groove running around the lower curvature of the guide rod hole at approx. the same depth as the 4513.
Is this a streak on my monitor or could there be a spacer somewhat like that on earlier 4516s except its purpose would be to pre-load the spring to increase its working pressure?

John

Click to expand...

Thanks Bill, the additional input makes sense. I was thinking about things backwards I guess. Often a problem for this left hander.

Anyways, I'm staying tuned to see what you come up with!

Hi BMCM,

It took me awhile but I finally made it over to where my guns are stored and took out the Shorty 45 MKII.

I HAVE SPRING STACKING!! But here is the weird thing, only with the brand new factory OEM dual springs....????

The springs that were in it don't stack.....as far as I can tell, going by your your photo examples. I suspect the springs that were in it were the originals as this Shorty 45 MKII has not been shot much. They were almost a 1/2 inch shorter than the new factory springs I tried putting in.

The original springs in it have no color left on them. The new springs are a light blue color. I think maybe you are onto something with these current production factory springs being too long. I got this batch last May from S&W.

These new springs matched the springs in my other 4513TSW's and those guns run fine.....although I had not checked them for spring stacking in the manner you have demonstrated here. I guess I will now.

I did notice that when reassembled the tip of the guide rod does not protrude from the slide at the Shorty 45's muzzle like my standard production 4513TSW's. It almost looks semi recessed. Is that how it is on your Shorty 45?

I will watch this thread anxiously to see what you come up with to rectify this situation. Ideally, I'd like to purchase a drop in replacement flat wire spring for the Shorty 45. I don't want to mill the guide rod or alter the gun in any way. But the Shorty 45 is too nice a pistol to let it become a safe queen. Regards 18DAI

Hi 18DAI

I'm still on the case.

Your Shorty sounds about the same as mine. I get a little more travel with the old set of springs too. With a new set of springs in there I lose nearly an 1/8" of travel vs no springs at all.

My guiderod is slightly recessed also. I think that is due to the front end of the Shorty slide being just a bit longer/thicker. I've got a couple other 4513 rods I checked it with. They're all about the same length and recess somewhat in the Shorty slide.

The guys at ISMI are sending me some stuff for T&E. I'll post results when I get the parts and have opportunity to get the the range.

Spoke with S&W today which wasn't of much help. I need to check back with them next week when the 3rd gen expert is back in the office.

Stay tuned

Cheers
Bill

I been out of the SW game for a while but when I was running my CQB hard, I called SW with my serial number and ordered springs for my PC CQB.

since it was a 4", I am sure they were not 4.25" 4566/4563 springs.

they would come in a ziploc type baggie with no part number.

back then you could talk to someone in the PC……I don't think you can do that anymore.

good luck

What word young William? Any luck other than bad?


Cat

Catshooter said:

What word young William? Any luck other than bad?


Cat

Click to expand...

Hiya Cat'

Nope, no bad luck here just too many irons in the fire as usual

Here's my test setup. ISMI sent me a 22lb rate 30 coil spring to try out. After some test fitting I eventually took off three coils and now have full slide travel.


No coil bind and no short stroking. Slide retracts fully to my reference mark.


So now I just need to get my poop together for a range outing.
I got a couple other things I need to wrap up for testing out so it'll be a bit longer before I can head across the river and give'er a thorough thrashin'.

Cheers
Bill

Looks pretty good. Let us know, please.


Cat