SW99 Guide Rod fitment?

S

Shoebox

New member
Hi all:

I have a SW99 compact chambered in .40 S&W. It went down on me at the range a while back (better there than some other time). Most of the spring perch sheared off, on the end that held the larger, outer spring in place. The spring popped out locking the gun and obviously rendering it inoperable.

Smith and Wesson mailed me a new one at no charge.

And now, the dumb question: I forget which way the guide rod seats. It seems that the smaller diameter spring with the metal end cap should go towards the front of the gun, with the larger diameter spring seated towards the rear.

However, I have tried it both ways and I cannot get the slide to go back into its proper position. It catches on something that seems out of place and will not make the final 1/2 or so of travel to lock itself onto the frame. Everything looks fine though, but I cannot get this gun re-assembled.

I have had this gun apart many times, although not recently, and am religious about cleaning and have never had this problem. Yes, I'm an idiot for not remembering which way the guide rod goes in. But the "manual" and the S&W homepage were both useless on this.

I'm not sure if the spring failure broke something I cannot see and wonder if it should go to a gunsmith.

Thanks!
 
Naturally, I don't pretend to be able to diagnose what's happening with your particular pistol, and if you suspect a problem to exist you ought to call S&W or take your pistol to a licensed gunsmith.

I can, though, offer some conversational info based upon my experience with my own SW99c, and a couple of others which I've examined and helped maintain as an armorer.

The large end of the double recoil spring/guide rod assembly is positioned toward the front of the slide. The small end (the metal plate) rests within the semicircular notch located toward the rear of the barrel, at the front of the barrel lugs.

It's been my experience that the compact model recoil spring/guide rod assemblies don't always 'rest' in their position, held in place under tension ... as the similarly shaped Glock subcompact assemblies do. Make sure that your recoil spring assembly remains in the proper position, once installed, with the rear end sitting down within the semicircular barrel notch, as you reinstall the slide onto the frame. This may take a bit of careful attention until you 'get the knack'. Otherwise the rear of the assembly may fall out of place.

Taske the EMPTY disassembled pistol and hold the slide & frame (with the barrel and recoil spring/rod assembly resting in its proper place) alongside each other ... with the frame rightside up and the slide UPSIDE DOWN, but positioned next to the frame as if the slide were in its in-battery position of it were actually on the slide. Notice how the rear of the recoil spring/rod assembly must fit in the curved area located at the front of the rather large locking block Walther designed for the 99 series.

Now, if the rear of the recoil assembly were to fall out of its proper position during reassembly of the slide onto the frame, and it were to become caught 'outside' the curved opening in front of the locking block, you can see how it might not fit into the front of the locking block, and might remain caught on the polymer frame surrounding the leading edges of the locking block. This might prevent the rear of the assembly from slipping back and in where it belongs, which might account for the approx 1/2" reduced slide travel.

While you have your assembled slide being held upside down, tip it to either side and see if the rear of your recoil spring/rod assembly falls to one side. If this happens when I go to reassemble a SW99c, it can cause the rear of the assembly to be incorrectly positioned during the last part of the slide's installation onto the frame, and stop the slide from completely being installed onto the frame.

I generally hold my SW99c upside down as I reassemble the slide onto the frame, visually making sure the rear of the recoil spring assembly remains properly positioned as I install the slide onto the frame. I've also done it by holding the slide & frame so the pistol is reassembled with the muzzle pointing straight down, as well, but I find it's easier to keep the recoil spring assembly properly positioned ... for me ... when holding the pistol 'upside down' during reinstallation of the (completely assembled) slide.
 
First, thanks a million for the reply. It is very well presented and easy to follow. I know asking for diagnosis on the forum is always iffy and I appreciate the time and help.

Notice how the rear of the recoil spring/rod assembly must fit in the curved area located at the front of the rather large locking block Walther designed for the 99 series.

Here's my problem: The new recoil spring/rod assembly doea not want to compress to fit into that semicurcular notch in front of the locking block.

As I mate the barrel and the rod assembly into the slide, the front/large end of the assembly drops willingly into the open "retainer" at the front of the slide. But the round metal plate at the rear does not want to drop into that semicircular notch. The whole assembly seems a bit too "long" and the springs do not want to compress (at least by hand) to allow me to drop the rear end into that notch.

EDIT: To clarify: To be more accurate, the problem is that when I drop the mated rod assembly and barrel into the slide, the assembly is too long and won't willingly compress to allow the barrel to drop into place. The square/rear end of the barrel is getting hung up at at the rear of the ejection port.

Never had this problem with the old/failed assembly. (Maybe that had something to do with its failure...)

I am hesitant to try and compress the rod assembly with a C-clamp to try and get it to compress. Any thoughts?

Again, thanks.
 
Okay, it's not unusual for the new assembly to seem slightly 'too long'. It can be compressed with finger pressure and slipped into place (like is done on Glocks, BTW).

Don't be surprised if this 'too long' condition doesn't last very long after some usage, though, and then the assembly almost seems 'too short', or untensioned, as I described in my first reply.

It is important for the front of the assembly to properly slip into place, too, before you slightly compress and slip the rear of the assembly into place in the semicircular notch at the front of the barrel lugs.
 
DON'T USE A CLAMP to compress the assembly. Finger pressure is sufficient. Firmly applied, perhaps, but sufficient ... ;)
 
To be more accurate, the problem is that when I drop the mated rod assembly and barrel into the slide, the assembly is too long and won't willingly compress to allow the barrel to drop into place.

The barrel has to be installed in the slide first, and then the recoil spring/rod assembly is installed into position against the barrel.
 
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