Cylinder Play

[drw2514]

So I've done some searching, and I've read the revolver check-out thread, but I still don't have an answer. So...

I've got a S&W 642-2 and I'm concerned about the movement of the cylinder. I can rotate the cylinder when it is supposedly in full lockup (trigger all the way back right before hammer falls) and the chamber/cylinder bore becomes un-centered with the barrel. How much is too much? Basically, I'm concerned that, upon firing, the bullet will impact the forcing cone too far off center resulting accelerated wear on the gun.

It's like this: looking down the barrel (gun unloaded, of course) if I rotate the cylinder counter-clockwise, it won't move much and I can't see any of the cylinder down the barrel. If I rotate it clockwise, I can see a good bit of cylinder on the left side of the inside of the barrel. Am I just paranoid? I understand that they aren't supposed to lock up completely solid (other than old colt "bank vault" revolvers) but this seems like it's too loose to me.

 

[loosecannon]

Since some movement is normal, it is very unlikely that your gun is defective. Holding the cylinder to either side will cause misalignment. You worry only if misalignment occurs during firing. All revolver barrels at the rear have a funnel shaped forcing cone which assists the bullet's jump from cylinder chamber to barrel. It would not be funnel shaped if alignment was always perfect.

If your revolver doesn't spit gas and or lead particles from the cylinder gap, then it's ok. If it does, this is easily remedied by warranty repair.

About the old bank vault /tight lock-up Colts, they could lock up dead tight and still have cyl misalignment, but with them the error was always in the same direction and to the same degree because the top of the hand deadheaded against the cyl ratchet. They were hell to work on.

loosecannon

 

[Majic]

Full lockup is to pull the trigger fully to the rear and allow the hammer to fall but don't release the trigger. What you have done is stopped the action part of the way thru it's cycle. The cylinder hasn't had time to rotate to the lockup position.

 

[drw2514]

Thanks for the quick replies.

I'm relatively sure it's nothing. I'm pretty paranoid.

And Majic--thanks for the clear up with the full lockup condition. I tried it that way too and there was just as much movement, as it seems that the cylinder was in the same position. If I'm understanding it correctly, the only thing holding the cylinder in place at the moment of lockup is the cylinder stop protruding from the bottom strap of the frame inserting into the tab on the cylinder... which is what it was doing while I was holding the trigger back before the hammer fell. I was just making it more difficult by holding the trigger when I could've let the hammer fall and had the same situation.

 

[HOME DEPOT GEORGE]

If I'm correct from reading past threads the only revolvers that went into "full" lockup were colts and one other that I cant remember now but it wasn't smith and wesson or ruger. They were supposed to still have some play even in full lockup.

 

[machinisttx]

If I'm correct from reading past threads the only revolvers that went into "full" lockup were colts and one other that I cant remember now but it wasn't smith and wesson or ruger. They were supposed to still have some play even in full lockup.

You are correct. Holding the trigger to the rear on a S&W or Ruger does absolutely nothing to aid lockup.

 

[KyJim]

Not to nitpick, but it's in "full lockup" even if it's a Smith and Wesson. There might, however, be just a bit of movement acceptable in full lockup. This is from Jim March's sticky on revolver checkout:

2) Thumb the hammer back, and while pulling the trigger, gently lower the hammer all the way down while keeping the trigger back - and KEEP holding the trigger once the hammer is down. (You've now put the gun in "full lockup" - keep it there for this and most other tests.)

3) With the trigger still back all the way, check for cylinder wiggle. Front/back is particularly undesirable; a bit of side to side is OK but it's a bad thing if you can wiggle it one way, let go, and then spin it the other way a fraction of an inch and it stays there too. At the very least, it should "want" to stop in just one place (later, we'll see if that place is any good). The ultimate is a "welded to the frame" feeling.

Personally, I don't buy used Smith and Wessons that have any front to back wiggle. I also won't accept much in way of lateral movement.

 

[JB696]

Actually, all Ruger double action revolvers are designed to lock up tight, just like a Colt or Charter Arms. But because of changes to the size and shape of the parts and sloppy production tolerances, this is not often found on an off-the-shelf production model. On paper, Ruger's patented "triple lock" design to hold the crane and cylinder securely in the frame is excellent. The centering pin in the middle of the extractor will lock snuggly in the hole in the recoil shield. The front latch will lock in it's slot in the lower front of the frame window. And the cylinder latch will lock into one of the notches in the side of the cylinder. If you look carefully at the ratchets on your extractor, next to the angled surface, toward the outer edge, is a flat surface that is lined up vertically with the frame when the cylinder is in the locked position. This is easy to see on an SP101 if you have one handy. After the pawl has turned the cylinder into position, the tip of the pawl rests against this flat surface on the extractor. In lock up, the pawl becomes lightly wedged between the right side of its slot in the recoil shield and the extractor. The tip of the pawl pushes the extractor to the left. Which turns the cylinder counter-clockwise. Which pushes the side of the cylinder notch against the cylinder latch. Which presses against the side of its slot in the bottom of the frame window. Simple, right? If the tip of the cylinder latch is the appropriate thickness, you have perfect barrel to cylinder bore alignment AND tight, consistent lockup.

But what happens in the real world? The hole in the recoil shield for the centering pin is drilled oversize. The crane latch at the front, which in the early years was square shaped at the tip for a snug fit, will have one side ground off, making it useless. So on most guns, the crane doesn't actually "lock". It floats side to side and the cylinder can be in a different spot when each round is fired. And down on the factory floor, the gun assembler grabs a cylinder latch out of the parts bin and snaps it into place. Then he hits the side of the pawl against a grinder until the gun will cycle without binding. And it's done. If the gun locks up tight, that's just a lucky fluke.

Finding just the right thickness of cylinder latch to set the bore alignment, fitting the tip of the pawl for tight lockup, stoning just the right amount of metal off the end of the crane tube to allow the cylinder to turn freely with no endshake........all of this takes a lot of time. If they did it at the factory a new SP101 would cost you $1200. But Ruger revolvers aren't designed to be sloppy. It's just the way it is with mass produced, affordable handguns.

Does it matter? It depends on the shooter. The bullet fired in a sloppy gun can wiggle its way around until it gets lined up with the barrel bore. And a sloppy gun can be reasonably accurate. This is because of the miracle of the forcing cone, which acts like a funnel. But a sloppy revolver is not usually accurate on all chambers. Or consistently accurate from one cylinder full to the next. And that matters to some people.

 

[dc202]

My Colt Pythons and my Colt Detective Specials lock up tight. My Ruger SP101 and my Performance Center S&W also does this. None of my other Smiths, including my 642, lock up tight under your described situation.

 

[machinisttx]

Not to nitpick, but it's in "full lockup" even if it's a Smith and Wesson. There might, however, be just a bit of movement acceptable in full lockup. This is from Jim March's sticky on revolver checkout:

I'm well aware of what's in his checkout thread. I also know how a S&W works, and it makes no difference whether the trigger is held to the rear or not(unless it's a DAO gun). Colts operate differently and DO lock up tighter when the trigger is held to the rear because of how the parts interact.

Personally, I don't buy used Smith and Wessons that have any front to back wiggle. I also won't accept much in way of lateral movement.

You must not buy very many then, because I have yet to handle one that didn't have some endshake-new or used. You're just leaving more out there for me to buy at a reduced price, do an hour's work on, and enjoy.

 

[whitebb]

I have found out newer colts do not bank vault tighten. Trooper MkIII and V's and their family counterparts (NOT Python) are loose like Smiths due to machine fitting and little to no handfitting. My Trooper MKIII has a little side to side play, and endshake that is at the outer limits. It would concern me but it doesn't spit lead (except out the barrel which is extremely accurate)