S&W 625-4 Action getting "Bound Up" during live fire

[GlockCanMan]

Mark your cylinders and then try it again. Does it always hang up on the same chamber?

[Aglifter]

The IL has been disabled, correct? (It locked up on my 625, when it was still stock.)

[futool]

Order me some extra washers for my parts stash

Checking Brownells And Midway tonight. I got ya bro.

[futool]

I had a similar issue with a 627, The sear pin was moving around ever so slightly and hitting the side plate. Centered it and swaged it in....has not re-occured.

Also interesting, but i'd imagine that once the pin moved out slightly and hit the side plate it would also mess with the action while unloaded.

I would keep it on the list of things to check. One thing infuriating about S&W design and manufacturing precision is that the hammer assembly and trigger assembly float back and forth on thier pins inside the frame. While live firing you not only get recoil pushing the gun back and up, the gun torques as it imparts spin to the bullet. These movements can shift parts into, and out of, interference in ways that are hard to replicate dry firing.

If you get serious, you'll want shims to set and space endshake and barrel gap, shims to center the hammer assembly in the frame and reduce drag, and shims to center the trigger assembly.

And that's just the beginning...

Oy vey. I just got into revolvers and learned how to strip this baby a few months ago. Boy do I have a lot to learn.

And I greatly appreciate all your help.

[futool]

Good advice from Waltermitty on this thread.

Want to come out to NJ?

I'll pay your entry fees at USPSA next Sunday.

[futool]

Curious if this revolver is shooting lead bullets? I had a M-14 with the old style yoke / gas shield and it would bind, when lead/lube spatter got between the cylinder and yoke.

I opened up the barrel forcing cone a tad.and made sure to shoot it wet with lube.

Tried 230 Gr lead and plated. Happens with both.

[futool]

Good advice from Waltermitty on this thread.

I was going to post the same thing. I had similar problems with my JM 625 and after a quick trip to a local gunsmith it is all better.

Cool, and a simple spacer fixed it? Was it a new S&W?

[futool]

Mark your cylinders and then try it again. Does it always hang up on the same chamber?

Nope. Starts off ok then gets progressively worse the more you fire.

[futool]

Ok, so i gapped the cylinder.

My thinest gauge is .0015 and i had to slightly pull the cylinder back to get it to slide between the barrel and cylinder. And at it's farthest point it's tight at .010. That's A .0085 length of travel.

So what's the preferred forcing cone to cylinder gap?

[bountyhunter]

How about powder/crud under the extractor 'star'? Happened to me but cyl was also hard to close at times.

Cleaned her up all puurdy like... Inside and out. Still happens.

Here is why it happened on one of my SW's:

Check the headspace between the breech face and the cyclinder ALL the way around. Some breech faces are not flat and have high spots. As the cylinder get hot and expands, the fired cases would start binding.

The headspace should be about .065 and anything under about .060 will cause binding.

[jhgtyre]

Good advice from Waltermitty on this thread.

I was going to post the same thing. I had similar problems with my JM 625 and after a quick trip to a local gunsmith it is all better.

Cool, and a simple spacer fixed it? Was it a new S&W?

It was used. The gunsmith said it was binding between the cylinder and the forcing cone. He did whatever magic makes that stop and it has been good

[Waltermitty]

Good advice from Waltermitty on this thread.

Want to come out to NJ?

I'll pay your entry fees at USPSA next Sunday.

Ok, so i gapped the cylinder.

My thinest gauge is .0015 and i had to slightly pull the cylinder back to get it to slide between the barrel and cylinder. And at it's farthest point it's tight at .010. That's A .0085 length of travel.

So what's the preferred forcing cone to cylinder gap?

Thanks for the invite to NJ, but I spent last week in the Florida Keys so I'll have to spend a while around here to keep the day job a little longer.

The forcing cone to cylinder gap is kinda one of those things that you get whatever you get when everything else is right due to tolerance stacking. There's a tolerance on the cylinder length, star machining, barrel set, etc. In my experience, anything between about .003" to .010" is tolerable, but with the numbers from your measurements you should be able to get a respectable .006" - .008" +/-.

If you had to pull the cylinder back to get a .0015" gage in, that's the classic example of a gun that will spin and dry fire great when clean and lubed, but will tighten up and refuse to run with a little heat and sticky powder residue in the gap.

A professional gunsmith would probably true and stretch the crane, square the crane end leaving just enough play for one or two shims. Then set final dimensions with the shims.

Others of us would buy a package of .002"and .004" shims and based on your measurements, stack two .004" shims where the crane meets the cylinder and see how she runs. If a .002" can be added and you can still "feel" some end play, it don't get much better than that; particularly if you begin thinking about reduced trigger pulls with lighter springs and... nah, stay away from the dark side.

Here's some shims if you haven't found them yet. http://www.brownells...58.aspx?ttver=2

[futool]

Good advice from Waltermitty on this thread.

Want to come out to NJ?

I'll pay your entry fees at USPSA next Sunday.

Ok, so i gapped the cylinder.

My thinest gauge is .0015 and i had to slightly pull the cylinder back to get it to slide between the barrel and cylinder. And at it's farthest point it's tight at .010. That's A .0085 length of travel.

So what's the preferred forcing cone to cylinder gap?

Thanks for the invite to NJ, but I spent last week in the Florida Keys so I'll have to spend a while around here to keep the day job a little longer.

The forcing cone to cylinder gap is kinda one of those things that you get whatever you get when everything else is right due to tolerance stacking. There's a tolerance on the cylinder length, star machining, barrel set, etc. In my experience, anything between about .003" to .010" is tolerable, but with the numbers from your measurements you should be able to get a respectable .006" - .008" +/-.

If you had to pull the cylinder back to get a .0015" gage in, that's the classic example of a gun that will spin and dry fire great when clean and lubed, but will tighten up and refuse to run with a little heat and sticky powder residue in the gap.

A professional gunsmith would probably true and stretch the crane, square the crane end leaving just enough play for one or two shims. Then set final dimensions with the shims.

Others of us would buy a package of .002"and .004" shims and based on your measurements, stack two .004" shims where the crane meets the cylinder and see how she runs. If a .002" can be added and you can still "feel" some end play, it don't get much better than that; particularly if you begin thinking about reduced trigger pulls with lighter springs and... nah, stay away from the dark side.

Here's some shims if you haven't found them yet. http://www.brownells...58.aspx?ttver=2

Haha, I was pulled to the dark side by that S.O.B Alec.

I ordered the Power Customs .002 & .004's last night. Hopefully that'll do the trick. I'll post some pics and the results once they come in.

Thank you ALL for the help and insightful revolver lesson.

[alecmc]

Thank you ALL for the help and insightful revolver lesson.

me too, learn something new everyday.

Edited January 18, 2013 by alecmc

[Waltermitty]

Good advice from Waltermitty on this thread.

Want to come out to NJ?

I'll pay your entry fees at USPSA next Sunday.

Ok, so i gapped the cylinder.

My thinest gauge is .0015 and i had to slightly pull the cylinder back to get it to slide between the barrel and cylinder. And at it's farthest point it's tight at .010. That's A .0085 length of travel.

So what's the preferred forcing cone to cylinder gap?

Thanks for the invite to NJ, but I spent last week in the Florida Keys so I'll have to spend a while around here to keep the day job a little longer.

The forcing cone to cylinder gap is kinda one of those things that you get whatever you get when everything else is right due to tolerance stacking. There's a tolerance on the cylinder length, star machining, barrel set, etc. In my experience, anything between about .003" to .010" is tolerable, but with the numbers from your measurements you should be able to get a respectable .006" - .008" +/-.

If you had to pull the cylinder back to get a .0015" gage in, that's the classic example of a gun that will spin and dry fire great when clean and lubed, but will tighten up and refuse to run with a little heat and sticky powder residue in the gap.

A professional gunsmith would probably true and stretch the crane, square the crane end leaving just enough play for one or two shims. Then set final dimensions with the shims.

Others of us would buy a package of .002"and .004" shims and based on your measurements, stack two .004" shims where the crane meets the cylinder and see how she runs. If a .002" can be added and you can still "feel" some end play, it don't get much better than that; particularly if you begin thinking about reduced trigger pulls with lighter springs and... nah, stay away from the dark side.

Here's some shims if you haven't found them yet. http://www.brownells...58.aspx?ttver=2

Haha, I was pulled to the dark side by that S.O.B Alec.

I ordered the Power Customs .002 & .004's last night. Hopefully that'll do the trick. I'll post some pics and the results once they come in.

Thank you ALL for the help and insightful revolver lesson.

Thank you ALL for the help and insightful revolver lesson.

me too, learn something new everyday.

We can celebrate when you get the gun running 100%. For now let's continue troubleshooting and fixing what we find as we go along.

And the next time someone tells you they like revolvers because they are simple and won't jam or malfunction, just smile and nod.

[futool]

Got the parts in and installed them yesterday.

Looks like it already had bearings inserted. 4x .004's and 1x .002.

I took out the old ones and added 6 of the new .004's.

Now the gap is .005 to .008.

I've very happy to report that the binding issue has been resolved.

17 bucks in parts and quick visit to Enos... Just awesome...

The only downside is that now I have no excuse for being such a poor shot.

Thanks to everyone once again for taking the time to help me out.

Nick

[Waltermitty]

Got the parts in and installed them yesterday.

Looks like it already had bearings inserted. 4x .004's and 1x .002.

I took out the old ones and added 6 of the new .004's.

Now the gap is .005 to .008.

I've very happy to report that the binding issue has been resolved.

17 bucks in parts and quick visit to Enos... Just awesome...

The only downside is that now I have no excuse for being such a poor shot.

Thanks to everyone once again for taking the time to help me out.

Nick

That's great that you got it running. Congratulations!

[Matt Griffin]

Doesn't that sound pretty extreme to anyone else, .018 of shimming? It might be time to get your yoke stretched or replaced.

[Waltermitty]

Doesn't that sound pretty extreme to anyone else, .018 of shimming? It might be time to get your yoke stretched or replaced.

I agree that's a lot of shims. It would be nice to get a good qualified gunsmith to diagnose the real problem. It could be a short yoke, or a number of other things.

But then again, if the barrel gap is ok and the gun runs fine, you could spend quite a lot of time and money for not much improvement.

[PatJones]

Check your cylinder notches for burrs. I had a customers gun with a burr at the front of one notch that prevented the cylinder stop from resetting. The stop moves forward when the trigger resets. The burr was preventing it from returning to the rear where the trigger could pull it down for the next cycle, locking up the action.

-pat

[Bill Sahlberg]

This also happened to me with a 627 and it was the cylinder timing hand that protruded .0005" too much.

[Hdbicker]

The problem is the cylinder heats up & expands. Take a hair dryer and heat up the barrel and cylinder. If the Cylinderhangs up as I expect it will, some of the blogs are correct. Smith cylinder to forcing cone should be about 6 thousands. Think about it, metal expands when heated. Give it a try. 1 thousand is not enough because of expansion. I worked on a bunch of Smith while at the chgo police academy. By the way Smith does not recommend washers, but uses a stretch method.

[Carmoney]

I worked on a bunch of Smith while at the chgo police academy. By the way Smith does not recommend washers, but uses a stretch method.

While that might be true, the sad truth is that Smith & Wesson has no idea how to tune their own guns. A couple years ago, when one of the S&W team members needed a gun set up for Bianchi, Julie grabbed a new gun out of inventory and sent it to me for the action work.

So that ought to tell you something.

[Waltermitty]

I worked on a bunch of Smith while at the chgo police academy. By the way Smith does not recommend washers, but uses a stretch method.

While that might be true, the sad truth is that Smith & Wesson has no idea how to tune their own guns. A couple years ago, when one of the S&W team members needed a gun set up for Bianchi, Julie grabbed a new gun out of inventory and sent it to me for the action work.

So that ought to tell you something.

That is the ugly truth. The way I learned about this whole problem and how to fix it in the first place was getting a gun to run *after* S&W "fitted" a new cylinder to my gun. They may say they do not recommend washers and use the stretch method, but in my personal experience, they don't do either one.

[futool]

I worked on a bunch of Smith while at the chgo police academy. By the way Smith does not recommend washers, but uses a stretch method.

While that might be true, the sad truth is that Smith & Wesson has no idea how to tune their own guns. A couple years ago, when one of the S&W team members needed a gun set up for Bianchi, Julie grabbed a new gun out of inventory and sent it to me for the action work.

So that ought to tell you something.

It absolutely does...

The Artisan that worked on my 625 knows Julie Golob.

That kinda sorta makes me two degrees separated from her. And she's way better than Kevin Bacon.