Now, this may be a problem of my own making. I installed the light spring set from Brownells. I believe that the return spring is 13 pounds. I have done this with at least four other S&W revolvers without a problem. The 627 freezes at the far end of the trigger pull and doesn't return, I have to push it forward. It feels like something is rubbing. I don't believe that this is a matter of an overly light spring, but rather it seems like something is rubbing. Where should I be looking for binding? Thanks..
New 627PC Trigger Reset Problem
- Thread starter Gary H
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Sure sounds like the return spring is too light, for the smoothness of the action right now. Try putting the stock spring back in and see if the problem goes away.
There are lots of parts moving in different directions as the trigger resets, and any of these could be a little rough. The 1st spot I would look to is the front bevel of the little ledge on top of the rebound slide. The place the hammer sits on, when at rest.
Sometimes breaking the front edge of this rased ledge will allow you to use a lighter reurn spring earlier. That lets the rebound slide get past the hammer a little easier.
A bit of polishishing there, just sort of matches what is going to happen anyway, in about 2000 rounds.
Good Luck...
Joe
There are lots of parts moving in different directions as the trigger resets, and any of these could be a little rough. The 1st spot I would look to is the front bevel of the little ledge on top of the rebound slide. The place the hammer sits on, when at rest.
Sometimes breaking the front edge of this rased ledge will allow you to use a lighter reurn spring earlier. That lets the rebound slide get past the hammer a little easier.
A bit of polishishing there, just sort of matches what is going to happen anyway, in about 2000 rounds.
Good Luck...
Joe
Another possibility: The trigger cams the cylinder stop forward against spring tension at the end of it's ( the trigger's) forward travel. If the cylinder stop spring is kinked or bent the resistance is increased, and with a reduced rebound slide spring the combination could be causing the trouble.
I have no idea what you plan to use this 629 for, but if it is in any way as a weapon I would ditch the light spring and go back to the stock one.
I have no idea what you plan to use this 629 for, but if it is in any way as a weapon I would ditch the light spring and go back to the stock one.
Revolver Armorer
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one thing leads to another - light sprigns
Bad thing to do, believe me. First, the mainspring hammer strut on the newest models hyper extended. In other words, the mainspring both supports and exerts pressure on the strut assembly to maintain mainspring tension. But this also affects other things, specificially springs. Such as changing the return spring to a lighter weight. Such hammer strut changes and other modifications to the design makes lighter springs in general, a sure failiure. When you have weak trigger return, your guns passive safeties are not working. The trigger return (or rebound spring) actually returns the rebound to the safe position in the hammer seat. Newer guns do not lend themselves so easily to "creative gunsmithing".
Bad thing to do, believe me. First, the mainspring hammer strut on the newest models hyper extended. In other words, the mainspring both supports and exerts pressure on the strut assembly to maintain mainspring tension. But this also affects other things, specificially springs. Such as changing the return spring to a lighter weight. Such hammer strut changes and other modifications to the design makes lighter springs in general, a sure failiure. When you have weak trigger return, your guns passive safeties are not working. The trigger return (or rebound spring) actually returns the rebound to the safe position in the hammer seat. Newer guns do not lend themselves so easily to "creative gunsmithing".
Revolver Armorer:
This is my first S&W with the frame mounted striker. I will need to get out Kuhnhausen's book just to understand what you are saying. The spring set that I purchased from Brownell comes with one mainspring and three rebound springs of varying weight. I gather that all springs should be left at factory levels.
This is my first S&W with the frame mounted striker. I will need to get out Kuhnhausen's book just to understand what you are saying. The spring set that I purchased from Brownell comes with one mainspring and three rebound springs of varying weight. I gather that all springs should be left at factory levels.
Gary H:
Another possible issue comes to mind. The new S&W revolvers (or at least most of them) that have frame-mounted firing pins also have MIM (Metal Injected Molded) hammers that are lighter in weight then earlier forged counterparts. Because of this they may require a heavier mainspring to get a reliable "hit." I haven't experiments with this because I only have one revolver with MIM parts, and it is a "safe queen."
Another possible issue comes to mind. The new S&W revolvers (or at least most of them) that have frame-mounted firing pins also have MIM (Metal Injected Molded) hammers that are lighter in weight then earlier forged counterparts. Because of this they may require a heavier mainspring to get a reliable "hit." I haven't experiments with this because I only have one revolver with MIM parts, and it is a "safe queen."
Revolver Armorer
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new mainspring struts & other parts
Gary,
Forget Kuhnhausens book on the older S&W revolvers. We are talking the newer revolvers with frame mounted firing pins does not apply. The MIM mainspring strut is snapped into place (like a jigsaw pizzle) and then hyper extended to maintain a slightly negative force on the mainspring. The trouble with Kuhnhausens book is the vitage of guns it deals with. Not to mention that none of these books will ever show you how to fit a ratchet assembly. Stuff like that is advanced and not relegated to books on gunsmithing. Funny but the first time I looked at the frame mounted firing pin. The part could easily be confused with a locking bolt under the barrel.
Gary,
Forget Kuhnhausens book on the older S&W revolvers. We are talking the newer revolvers with frame mounted firing pins does not apply. The MIM mainspring strut is snapped into place (like a jigsaw pizzle) and then hyper extended to maintain a slightly negative force on the mainspring. The trouble with Kuhnhausens book is the vitage of guns it deals with. Not to mention that none of these books will ever show you how to fit a ratchet assembly. Stuff like that is advanced and not relegated to books on gunsmithing. Funny but the first time I looked at the frame mounted firing pin. The part could easily be confused with a locking bolt under the barrel.
Revolver Armorer:
I appreciate your guidance with regards to this problem. I enjoy simple gunsmithing duties. I gather that the newer Smiths are somewhat retrograde in design. That said, it seems that you are saying that stock springs and a good polish is about the best you will do should you want the gun to be reliable.
I appreciate your guidance with regards to this problem. I enjoy simple gunsmithing duties. I gather that the newer Smiths are somewhat retrograde in design. That said, it seems that you are saying that stock springs and a good polish is about the best you will do should you want the gun to be reliable.
Revolver Armorer
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- Feb 8, 2003
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new vs. older S&W wheelguns
Gary,
Actually, a lot more can be done for older guns, as opposed the newer variety with MIM parts. My favorite is refitting the cylinder stop to ensure the gun will pass a Match Plug Rod guaging test for cylinder/forcing cone centerline alignment. Overall, that operation does a lot to protect the forcing cone against wear and give a measure to precision to the action as the cylinder indexes and locks into centerline. On an older gun I almost always polish the rebound slide and get the trigger return/hammer compression force correct by feel, gauging and bench tests: i.e. single action weight (digital and steel weights), the firing pin protrusion and brisk trigger return (carefully watching the indexing in both slow and fast action operation).
Like I said, the mainspring strut on newer guns is made that way to stop folks from monkeying with the springs. The fact that the mainspring strut is snapped into place and not pinned can create problems with low intertia mainsprings. Sure in theory basic tuning can be taught to a lot of folks. However, the person is being given guidance should be done by someone with formal training, appripriate factory warnings and bulletins to insure all bench tests are being conducted and the gun is safe. Most factories want nothing to do with giving gunsmithing classes. I wish they would, hoever. We live in terrible times for that with liability concerns.
About the only thing I do to a newer style guns (outside of replacing all the internal lockwork with expensive carbon forged parts). Would probably involve adjusting the single action pull with a fixture and precision adjustments and refit the double action sear with one that was given incessant carefull fittting by yours truly.
Gary,
Actually, a lot more can be done for older guns, as opposed the newer variety with MIM parts. My favorite is refitting the cylinder stop to ensure the gun will pass a Match Plug Rod guaging test for cylinder/forcing cone centerline alignment. Overall, that operation does a lot to protect the forcing cone against wear and give a measure to precision to the action as the cylinder indexes and locks into centerline. On an older gun I almost always polish the rebound slide and get the trigger return/hammer compression force correct by feel, gauging and bench tests: i.e. single action weight (digital and steel weights), the firing pin protrusion and brisk trigger return (carefully watching the indexing in both slow and fast action operation).
Like I said, the mainspring strut on newer guns is made that way to stop folks from monkeying with the springs. The fact that the mainspring strut is snapped into place and not pinned can create problems with low intertia mainsprings. Sure in theory basic tuning can be taught to a lot of folks. However, the person is being given guidance should be done by someone with formal training, appripriate factory warnings and bulletins to insure all bench tests are being conducted and the gun is safe. Most factories want nothing to do with giving gunsmithing classes. I wish they would, hoever. We live in terrible times for that with liability concerns.
About the only thing I do to a newer style guns (outside of replacing all the internal lockwork with expensive carbon forged parts). Would probably involve adjusting the single action pull with a fixture and precision adjustments and refit the double action sear with one that was given incessant carefull fittting by yours truly.
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