Tight cylinder gap fix?

[LawofThirds]

I've got a nickeled 19-4 2 1/2" that measures barely .001 on the cylinder gap. There's absolutely no endshake and the cylinder is quite tight on the other end as well.

I want this gun as a carry gun, it's a perfect fit and my only reservation is that the cylinder starts to bind within 20 rounds. I am not comfortable with a gun that on the second cylinder has a propensity for binding to the point where the action is bound solid.

Is sending the gun off to a gunsmith and having the forcing cone recut and set back to .003-.004 my only option or is there some other fix that's available?

If the smith is the only option, who does good revolver work that doesn't have a 6 month or more wait?

 

[David E]

Before you send it off, swing out the cylinder and push in the ejector rod. Holding it like that, take a toothbrush and clean out the area under the extractor star and the cylinder face where the extractor star seats. It just might solve your problem.

 

[LawofThirds]

It would if I routinely failed to clean my firearms properly. However, this is a gun that spends most of its time being clean enough to eat off of.

 

[Oyeboten]

Check the gap at the rear first...might be something going on effecting the rear, which is keeping the Cylinder 'forward' too far.

 

[LawofThirds]

That was what I figured was the issue at first, but after careful examination, disassembly and measurement, I couldn't find anything that would be forcing it forward. There's no endshake shims and the recessed cylinder is only .015 away from the blast shield so there's very little play room on that end (it won't accept a round that has an even slightly high primer).

 

[Steve C]

Lead that's vaporized from the base of lead bullets can accumulate enough on the face of the forcing cone to close up the cylinder/forcing cone gap and lock up the cylinder. I had this happen on a Ruger Security Six, the first revolver I owned 35 years ago. I took it to the gunsmith and he told me what had happened. He locked the gun in a vise with the cylinder open and dressed off the back of the forcing cone with a flat file, checking the gap with a feeler gauge every pass or two to get the proper gap.

I stopped shooting soft swagged lead bullets at magnum velocities out of it and never had a recurrence of the problem.

 

[W.E.G.]

Can a loose ejector rod cause the cylinder to move forward?

 

[Old Fuff]

If this is a nickeled gun I wouldn't file anything. Doing so is a good way to start it peeling. Otherwise if no other answer is found the only solution might be to adjust the cylinder's length, and then if necessary strip and re-nickel it. Too tight a gap is most unusual.

 

[rcmodel]

Can a loose ejector rod cause the cylinder to move forward?

No.

rc

 

[LawofThirds]

Hmmm.

The forcing cone doesn't have the usual "slick" look of heavy leading on its face but there's always a chance that I've somehow missed some. What do you guys use for cleaning nickeled guns that's hard on lead and soft on the copper that's holding that nickel on?

 

[David E]

the only solution might be to adjust the cylinder's length

Or shorten the barrel. If this gun used to work just fine, then something changed.

If the OP is one of the rare few that remembers to routinely clean underneath the extractor star, then maybe it's a lead build-up on the forcing cone.

Maybe the OP in Post #10 has ID'd the problem.

 

[Confederate]

Many people say that .004 is the perfect gap size, but years ago tests done by the gun manufacturers convinced them that .006 was the way to go. To me it's never made any difference; however, .006 also had a positive effect on accuracy (at least that's what was reported back in the early 80s). S&W also found that a .006 almost always ensured ideal headspace for their revolvers. If the gap was too tight, the headspace was often excessive (which is something you might want to check). But if you're getting consistent discharges, you're most likely okay.

Your best bet is to put the gun in a padded vice, grips up and the cylinder removed. With a large flat file, remove just enough steel on your barrel to open the gap. Some people will scream about this, but you won't affect the barrel throat in the least. Make sure you remove steel in steady, forward strokes. It doesn't take much to open the gap, so don't get carried away.

 

[LawofThirds]

The gun was purchased second hand. The firearm works fine but has had the nasty habit of starting to bind after 20 rounds on average since I purchased it. After figuring that out the first time I took it out, I've started cleaning the face of the cylinder until there's no residue whatsoever, which means a good 15 minutes with a bronze brush.

I would think that just recutting the forcing cone/dressing the face of the forcing cone would be the most effective treatment.

 

[David E]

I've started cleaning the face of the cylinder until there's no residue whatsoever, which means a good 15 minutes with a bronze brush.

That's good, but to make sure we're on the same page, I had suggested cleaning UNDER the EXTRACTOR STAR, at the other end of the cylinder.

 

[LawofThirds]

I know which end of the cylinder is the extractor star. But hey, thanks for the assumption that I know nothing about a revolver.

Perhaps I should be more clear about my cleaning statement. After I went out, shot it 20-odd times, had the cylinder start to bind, and took it home, I realized the cylinder gap was very close. I then disassembled the cylinder/yoke assembly, cleaned everything, measured gaps, used a bit of nonpermanent locktite on the extractor so it won't back out etc. Since that time, in order to get the most range time out of the gun, I have cleaned the front of the cylinder (you know, the bit in front) very aggressively, removing any spec of fouling to the point where there's no longer darker rings.

I've owned other 19's in the past and have other revolvers currently, none of them have had these binding issues within the first 100 rounds (100-200 is about where my other smiths will start feeling a little sluggish).

 

[Old Fuff]

I would think that just recutting the forcing cone/dressing the face of the forcing cone would be the most effective treatment.

It would if the revolver was either blued or stainless. As it is if you cut through the nickel plate it might start to fleck or peel. Given that, if no better solution was found it would be better to increase the gap by removing material from the front cylinder face, and then stripping and re-nickel plating the cylinder. Doing otherwise would require removing the barrel from the frame - if the job was done right.

 

[David E]

thanks for the assumption that I know nothing about a revolver.

You are the one totally perplexed and you are the one asking for help.....

Send it to S&W and have them fix it.

 

[dfariswheel]

The first thought in a situation like this is that something else is wrong somewhere.

Barrel/cylinder gaps did vary slightly in the old days, and in todays two piece barrels they seem to fluctuate much more.
However, the fluctuation tends to be for larger, not smaller gaps these days.
In the old days, you might see a gap tighter, but not that tight.

My suspicion is that something is wrong here, and I'd find out what that is before doing anything.
At first hearing, it sounds like a mis-fit barrel, which immediately is cause for suspicion that an amateur replaced the barrel.
If it was a mis-fit factory barrel, the fix would be to trim the rear of the barrel to the correct gap, but NOT with a file.
The correct method is with a special facing cutter that works down the bore.
Since so little would have to come off, the forcing cone probably wouldn't need re-cutting and lapping.

However.....
A prime rule of gunsmithing is to be CERTAIN what a problem is before altering anything. Otherwise you're just shooting in the dark hoping to hit on the problem by luck.
If that turns out not to be the problem, you've just screwed up a good barrel.

In this case, I'd return the gun to the experts....S&W.
Whatever the problem, they can diagnose and repair it the right way and have it back to you fast and for a very competitive cost.

 

[LawofThirds]

And finding a 2 1/2" barrel for a 19 aint gonna happen cheaply.

I think I'll take the question to S&W and see what they do.

 

[351 WINCHESTER]

Back in the day when Customs issued revolvers they approached s & w and gave them their own specs. for their CS-1. That was all well and good until the guns were fielded and all failed. Every one had to be redone as the b/c gaps were way too tight along with some other problems that elude me at the moment.