Pin/Rod in Rebound Spring?!

[Gunhohulk]

I recently acquired a 629-4 mountain gun that was in pretty good shape but in need of a good cleaning. I took it apart last night and when I pulled the rebound slide out I found a small stainless pin/rod in the rebound spring. It almost looks like the end of a j frame center pin that has been cut down to 1/2" or so in length.

Has anyone seen something like this before? Is it an old truck of the trade or did bubba get ahold of this thing? Everything else on the gun seems to check out and the only other indication someone messed with the internals is that the face of the trigger seems to have been polished but was done well to my eye. Either way I don't think it's going back in when I put things back together unless somebody can confirm this is a factory feature I am just ignorant of.

Cheers.

 

[snw19_357]

It's an old truck of the trade for N frames. That pin is the overtravel stop.

 

[Protocall_Design]

It's from the factory as a trigger stop, but useless as they are always too short to do any good. If you want to make your own longer one, you will need to get it on size or minus about .002 to be useful. They don't have that kind of time to fit them at the factory. I just leave them out of my guns.

 

[Alk8944]

Like they said^^^^ it's intended to be an over-travel/trigger stop. It is peculiar to N-Frame revolvers. If you put it back in the round end goes forward. The gun will function just fine without it so just leave it out if you wish.

 

[Gunhohulk]

Looks like you learn something new everyday! This is the first I've heard of this but now that I think of it I have yet to take any of my other N frames apart, just J's & K's. Thank you all for the information.

 

[walter o]

Every body talks about the single action trigger on a colt PYTHON they have NO overtravel. i set up a 686 with a pin in the rebound spring and stoned the action and both guns are Equal in single action the 686 trigger STOPS as the hammer breaks perfectly . The stop is not set up for double action , if it is single action probably wont work properly.It takes time and patience to fit the pin.in and out. File pin when you get close stone .The front of the pin needs a radius to sit in the trigger rebound slide drilled hole exactly the same every time. Set up to just let the trigger release the hammer sear
to me it makes a world of difference try it se e if you like it ,you have not made any permanent modifications,.

 

[HeloMt]

One thing to be cautious of is that if the overtravel pin is too long it puts too much mechanical pressure on the rebound spring stud. That is a fixed stud in the frame. If the overtravel pin is too long, the rebound slide as pushed by the trigger, forces the overtravel pin into the rebound spring stud. At the armorers school we were instructed to remove them from duty guns to prevent undo stress or possible breakage of the rebound spring stud. My agency had Model 28's, so the overtravel pins were present in a lot of our revolvers.

 

[walter o]

Above post correct.I usually take out the main spring and use thumb pressure to move the hammer watching the rebound slide touching the frame pin ,just a kiss no more

 

[cmansguns]

The PIN or ROD...no factory listing?

Maybe I'm misunderstanding this OP. I'll call this trigger overtravel stop a ROD, just to differentiate the factory part called the rebound slide PIN which is the pin that is actually in the top of the rebound slide itself.

If I'm also understanding correctly, the PIN or ROD being discussed here is found inside of the rebound slide spring coils.

Please correct me if I am wrong!

If it is the one found inside of the spring coils, then I'm wondering why I cannot find any parts lists, or schematics that show this item.

Case in point: I've posted a bunch of stuff about my Model 25-2 (1972) that I once thought was original, but turned out to have been modified for competition years before I bought it.

The modifications for competition (by whom or when I do not know) resulted in a very accurate sweet shooting 45 acp hardball (230 gr FMJ) with a 2-3/4 lb SA, 6-1/2 lb DA trigger pulls.

The mods: Double ball detent yoke lock, lightly ground mainspring, strain screw ground to .5665" lg, polished rebound slide, shortened rebound slide spring (15 coils - 1.0075" lg), trigger overtravel stop ROD measures .6955" lg, Pachmayr 1 piece "Gripper" rubber combat grips

I wanted to sell this gun and decided that the trigger pulls might be too light for potential buyers so I went ahead and bought some factory new parts from Numrich and replaced the competition parts and swapped back to the original S&W Target grips. Parts replaced were: new mainspring, new strain screw (.5885" lg), new rebound slide and spring (18 coils - 1.255" lg),
and since I did not see any description anywhere of the ROD, I left it out.

Results were: SA trigger pull = 3lb-9ozs; DA = 11lb-5ozs.

Since the ROD I found installed measures exactly .6955" lg, does anyone know what the original factory supplied rod in an N frame measured? Why is this item not shown on any parts lists or schematics?

Obviously (to me at least) it appears to have no effect on anything as my gun functions fine in either competition setup, or factory stock, only difference being the trigger pull weights, so wondering why S&W even designed this part to begin with.

 

[walter o]

cmansguns
In my limited experience each rod must be hand fitted to the individual fire arm When you had all the custom components in the mod 25 did you notice a light trigger stop because of the stop rod?This an apparent advantage of the trigger stop if set correctly in my experiences.
but i am just a tinker .Others may find difference results.
I think that the slight movement of the trigger after it releases the hammer may cause the finger to cause the whole gun to move and disrupt the sight picture and accuracy. The pin stops the free movement of the trigger finger.
I have noticed that many of the older manufactured S&W were hand fitted by the craftsmen to have very little movement after the sear relies of the hammer from the trigger

 

[HeloMt]

Walter O is right. Each length will be different, as that is how the adjustment to overtravel is accomplished. You are correct, the overtravel pin or rod resides inside the rebound spring. It make mechanical contact with the inside of the rebound spring slide and the frame mounted rebound spring stud to the establish the amount of trigger overtravel desired in single action shooting.

 

[Jim Watson]

I noticed a little backlash twitch in my M686 that my M67 with trigger stop did not have. So I tediously filed a rod to fit and it helped.

 

[Walter Rego]

I tried one time to fit a piece of drill rod to the correct length to act as an overtravel stop and eventually gave up. And I am a pretty patient guy.

While not seen on N Frame guns, some eras of K and L frame guns had a slot in the frame behind the trigger for a tiny oval shaped trigger stop. Many times they are missing, either never installed by the factory or removed due to the factory caution that they were not recommended for duty guns because of the possibility that they could work themselves loose and prevent the gun from firing.

I did successfully install them on several of my K frame target guns and used some blue Loctite on the securing screw. The triggers feel great and I'm not concerned with the reliability factor. You can see the stops on these Model 14 and Model 17 guns.

 

[snw19_357]

If I'm also understanding correctly, the PIN or ROD being discussed here is found inside of the rebound slide spring coils.
...
If it is the one found inside of the spring coils, then I'm wondering why I cannot find any parts lists, or schematics that show this item.

Because Marines like (need) pictures.
Here are a 4 screw M27, 1974 M27, 1982 M28 and 1967 M29 diagram showing the rod (#5306) which S&W just calls the trigger stop.

 

[cmansguns]

Learnin....learnin....learnin.....

Man o man....am I ever learning...someday I MIGHT even know a lot about S&W revolvers. I do admit..I love precision machinery and these fine revolvers are just the ticket for this old guy to keep learning on.

So...thanks to SNW19 357.....us old ARMY guys like (need) pics too! My bad for only looking at Numrich schematic.

Also helomt and walter o are absolutely correct and right on the money...My trigger stop rod has one end absolutely square, and the other end is rounded. Also someone put two dimples near the round end. You guys had me curious so I put all the competition parts back in the Model 25-2 including the trigger stop rod (round end in first), remeasured SA trigger pull with my Lyman digital...still 2-3/4 lbs but NOW I do feel the action of the stop rod.....there simply is NO trigger slop, movement of any kind, in any direction!

I am feeling better, and better about whoever set this gun up years ago and since the gun is fun at the indoor range, but only punching paper, I'm checking around to see if the one outdoor range I know of has either steel plates, silhouette or other outdoor targets available where I could really put this gun through it's paces.

Heck...I may not even sell this one...got plenty 45 acp, moon clips, BMT loader, time (well don't tell the wife) so sounds like fun.

Thanks to all.............just like the OP said above.......learn something every day on this Forum.

 

[walter o]

the 2 punch marks at the rounded end are probably to lengthen the stop rod just a bit. ths is how precise the length must be.

 

[rvolvr]

Kuhnhausen S&W 5th edition, pg. 104, Figure 130 briefly notes the N-Frame trigger stop pin as a custom-fit installation. Uncharacteristically for Mr. K, he makes no mention of the potential danger to the integrity of the rebound slide stud if the pin is too long.

 

[Retired W4]

Round end to the front!! And now i know why. Thank you.,

 

[walter o]

Kuhnhausen S&W 5th edition, pg. 104, Figure 130 briefly notes the N-Frame trigger stop pin as a custom-fit installation. Uncharacteristically for Mr. K, he makes no mention of the potential danger to the integrity of the rebound slide stud if the pin is too long.This is true if the trigger is pulled with the side plate off of the gun .which we are told never to do. with the side plate on the gun the pin is captures on both ends ,can't bend or break.In this case the trigger pull would drastically increase just before the hammer was released
or maybe stop the trigger from releasing the hammer Try bending a steel rod 1/2 l0ng and 3/32 dia. with your finger