S&W 617 trigger issue

[xjwalt666]

I'm working on a friends 617 just doing the normal polish and cleaning up the internals to smooth out the trigger a bit. Before doing any work to it the trigger has an extremely hard break. When pulling the trigger as soon as the cylinder stop moves down the cylinder snaps to the next position. When it does this the trigger feels like its hitting a wall. If you back the strain screw way out it cycles thru just fine. I've gone thru and checked everything and there is nothing binding when there is no spring pressure. But as soon as the screw is turned in  it starts to get hard to pull again. Single action has no issue and when you pull the hammer back manually there is no binding or anything. Everything appears to be lined up properly. The cylinder spins free and doesn't bind at all when the internals are removed. Now I'm kind of stuck. I've worked on quite a few smiths including 4 or 5 617's and have never encountered this problem. Any ideas before I have him send it back to S&W or to a good revo smith?

[Toolguy]

The only thing I can think of offhand is that the hand may be too long and putting pressure on the ratchet before the cylinder is released underneath. This would be possible if someone got an L frame hand in a 6 shot gun. Cocking single action would raise the trigger a little bit later in the cycle. If a 10 shot gun with the hand narrowed at the top, then maybe an L frame hand was accidentally altered at the factory. This is all total speculation based on the clues. I have never heard of this happening before.

[xjwalt666]

13 hours ago, Toolguy said:

The only thing I can think of offhand is that the hand may be too long and putting pressure on the ratchet before the cylinder is released underneath. This would be possible if someone got an L frame hand in a 6 shot gun. Cocking single action would raise the trigger a little bit later in the cycle. If a 10 shot gun with the hand narrowed at the top, then maybe an L frame hand was accidentally altered at the factory. This is in total speculation based on the clues. I have never heard of this happening before.

 Was thinking it probably has something to do with the hand but I can honestly say I would have no clue where to start with that. It is a ten shot and it’s a newer model with the lock. Everything else that I’ve looked at checks out fine. The hand does have a narrow area at the top and where it engages the cylinder does have some what looks to me like abnormal wear. I may suggest that he send it to S&W or find a good revo guy around our area to check with. 

[xjwalt666]

To add, when pulling the trigger to stage it for the next shot, at about 1/4 pull it hits the wall. There is no slowly pulling it to the break it just snaps by and drops the hammer. I’m going to try to get a video of it this afternoon and find a site to host it on and link it here. 

[pskys2]

If the mainspring is knuckling it can feel kind of like that.

Knuckling is caused by not having enough arch at the top.

If you have another mainspring try it.

[DS-10-SPEED]

2 minutes ago, pskys2 said:

If the mainspring is knuckling it can feel kind of like that.

Knuckling is caused by not having enough arch at the top.

If you have another mainspring try it.

Is that something you can watch happen with the grip off?

[pskys2]

13 minutes ago, DS-10-SPEED said:

Is that something you can watch happen with the grip off?

Not really.  And it's not recommended to use full mainspring pressure with the side plate off. It's hard on the trigger stud to put full mainspring pressure on with side plate off.

If you can't feel or see any issues with no mainspring attached, try attaching the main spring and tightening the strain screw just enough so it stays put then with side plate off try the trigger.  It should be a very light pull.  If it does create that wall feel, and the mainspring has no arch at the top, then it is likely knuckling.

Don't force it though, and don't tighten the mainspring down all of the way with no side plate on.

Re-reading your question, with the grip off, back the strain screw off until the mainspring has very little pressure, just enough that it stays put.  Then try the trigger if the wall is still there, take the mainspring out and try again.  If the wall isn't there, look at the mainspring it should have an arch at the top.

Edited February 5 by pskys2

[DS-10-SPEED]

4 minutes ago, pskys2 said:

Not really recommended, hard on the trigger stud to put full mainspring pressure on with side plate off.

If you can't feel or see any issues with no mainspring attached, try attaching the main spring and tightening the strain screw just enough so it stays put then with side plate off try the trigger.  It should be a very light pull.  If it does create that wall feel, and the mainspring has no arch at the top, then it is likely knuckling.

Don't force it though, and don't tighten the mainspring down all of the way with no side plate on.

I think you thought I said trying it with the side plate off, I said grip, side plate on.

[pskys2]

2 minutes ago, DS-10-SPEED said:

I think you thought I said trying it with the side plate off, I said grip, side plate on.

Yes reread my response, i adjusted it.

[ysrracer]

If only there were some kind smith that worked on guns. That would be cool

[Bosshoss]

2 hours ago, xjwalt666 said:

To add, when pulling the trigger to stage it for the next shot, at about 1/4 pull it hits the wall. There is no slowly pulling it to the break it just snaps by and drops the hammer. I’m going to try to get a video of it this afternoon and find a site to host it on and link it here. 

Possible that the sear is too short. The sear starts everything moving and then hands off the movement to the hammer for the last part of the stroke. If the sear is too short the trigger bumps into the hammer on the hand off. If it is really short it will stop the movement. If it is close it will have a hard spot and then will slip past the hammer.

Might try dryfiring with cylinder open and cylinder release held back. If it still does it then it is something in the action.

If it goes away with the cylinder open it is in the timing(ratchet's) 

[Toolguy]

That sounds like a reasonable assessment.

[Vic]

"Some kind of smith that worked on guns"

I can recall days of old at the first couple IRCs, Charlie Prest would sit at a makeshift bench, between stages he had to shoot. He always had a couple guys standing in line to get some kind of repair done to their revolver. 

One moment you could watch him stretching a yoke to alleviate end shake, next time you pass by he was doing a trigger job. Hell, a guy had to wait all of 20 minutes to get a job done.....man those were the days. 

[xjwalt666]

3 hours ago, Bosshoss said:

Possible that the sear is too short. The sear starts everything moving and then hands off the movement to the hammer for the last part of the stroke. If the sear is too short the trigger bumps into the hammer on the hand off. If it is really short it will stop the movement. If it is close it will have a hard spot and then will slip past the hammer.

Might try dryfiring with cylinder open and cylinder release held back. If it still does it then it is something in the action.

If it goes away with the cylinder open it is in the timing(ratchet's) 

I tried this method of dry firing with the cylinder open and the problem persists. So I assume it is something within the internals. I guess back to S&W it goes. I am not comfortable with doing anything further with this one. Thanks for the advice. I am going to try a different main spring as mentioned above to see if it may be a spring issue. 

[xjwalt666]

3 hours ago, Bosshoss said:

Possible that the sear is too short. The sear starts everything moving and then hands off the movement to the hammer for the last part of the stroke. If the sear is too short the trigger bumps into the hammer on the hand off. If it is really short it will stop the movement. If it is close it will have a hard spot and then will slip past the hammer.

Might try dryfiring with cylinder open and cylinder release held back. If it still does it then it is something in the action.

If it goes away with the cylinder open it is in the timing(ratchet's) 

I just tried this again with the strain screw barely tightened to not put too much pressure on the pins. I can visually see the sear "bump" the hammer as you say right as it hits the "wall". So I would assume that would mean that either the hammer or trigger or both are either out of spec or one of the pins are bent. 

 

Now my question is, would it be acceptable practice to swap out another hammer and sear from a known good 617 to experiment just for testing purposes with dry fire only? Or should I just have him get a new set fitted?

[Bosshoss]

1 hour ago, xjwalt666 said:

I just tried this again with the strain screw barely tightened to not put too much pressure on the pins. I can visually see the sear "bump" the hammer as you say right as it hits the "wall". So I would assume that would mean that either the hammer or trigger or both are either out of spec or one of the pins are bent. 

 

Now my question is, would it be acceptable practice to swap out another hammer and sear from a known good 617 to experiment just for testing purposes with dry fire only? Or should I just have him get a new set fitted?

Hammer and trigger are OK it just needs a new sear fitted.

Sear is the black piece fitted to the hammer that starts the hammer moving back.

[xjwalt666]

33 minutes ago, Bosshoss said:

Hammer and trigger are OK it just needs a new sear fitted.

Sear is the black piece fitted to the hammer that starts the hammer moving back.

Gotcha. Thank you. 

[Toolguy]

You could still swap out a whole hammer to see how it does. Nothing to lose.

[xjwalt666]

8 hours ago, Toolguy said:

You could still swap out a whole hammer to see how it does. Nothing to lose.

I’m going to give this a go tonite and see what happens. 

[xjwalt666]

I ended up trying out swapping the hammer from my 617 into his. Checked sear engagement with the side plate off and everything moved smoothly. Put it all back together and it cycles nice and smooth. So I guess I'm going to order a new hammer for him and hopefully get this thing up and running like it should again. Thanks for all the help and suggestions. 

[RH45]

On 2/5/2024 at 7:31 PM, Toolguy said:

You could still swap out a whole hammer to see how it does. Nothing to lose.

Toolguy, 

Could you please P.M. or email me, when you get time?

 I have a question, and TRIED to contact you via your profile, but apparently doing something wrong

Thanks!

Randy