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Cylinder timing check?
- Thread starter marca
- Start date
Radicalcleric
New member
Don't know about using rods. Just cock the hammer then try to turn the cylinder. If it moves a bit then locks it is out of time. If it locked up solid after cocking the hammer, and the cylinder doesn't turn any more, then it is likely OK.
The test you describe is for cylinder/chamber alignment. Kuhnhausens' method of checking timing is to hold the unloaded gun with the bottom of the trigger guard in the palm of your hand, with a VERY light finger tension on the cylinder, and draw the hammer back until it is cocked. The cylinder bolt should drop into its' notch just before the sear sets. Same thing for DA - the cylinder bolt should lock just before the hammer is released. If your cylinder is locked each time, as you cycle through your test, then you need a gunsmith. If, after you pull and hold the trigger, you can move the cylinder, enough so that the bolt latches in the notch, you still need a gunsmith - just for different reasons.
I favor the "light test" variant:
http://www.thefiringline.com/forums/showthread.php?s=&threadid=57816
...but the "range rod" method with the gun at "full lockup" works too.
If it's off far enough, it's gunsmith time.
http://www.thefiringline.com/forums/showthread.php?s=&threadid=57816
...but the "range rod" method with the gun at "full lockup" works too.
If it's off far enough, it's gunsmith time.
The cylinder bolt should drop into its' notch just before the sear sets. Same thing for DA - the cylinder bolt should lock just before the hammer is released. If your cylinder is locked each time, as you cycle through your test, then you need a gunsmith
I have played around with my 4 S&Ws for some time now trying to identify whether or not they have a decent timing on them, only 2 of them are what I consider to be perfect and it's not surprising to me because they are the ones in the closest to "new" condition that I have.
Hopefully I can explain what the 2 guns are doing so that it's easy enough to understand.
My 2 guns that I know need a timing job, fall on both sides of the "you need a gunsmith" suggestion. My oldest gun, a postwar 38/44 has still got relatively good timing in that on 4 out of the 6 chambers the bolt will lock up just as the hammer sets for single action pulls, with a finger lightly dragging on the cylinder 2 of the chambers will not rotate entirely into position and lock when the hammer sets. However, when you pull the trigger the chambers will both rotate into position with the additional reward travel. On double action, all 6 chambers will lock up just before the hammer falls. For a 40-50+ year old gun, it's held up pretty darned well.
The other gun that I am 100% certain needs a timing job, is my Model 29. From the discription given, it sounds like the cylinder stop is engaging way too early in the trigger pull for single action or while setting the hammer for a single action pull. I would assume the hand is a bit too long which is what causes it to do this, does having a revolver that locks up it's cylinder too soon cause accelerated wear or why exactly is it a bad condition?
On a whole, the 29 needs work, it's got a bit of end shake, doesn't have what I consider to be perfect alignment of the chambers/barrel, and the timing seems to be a bit off. If the end shake is fixed, I'm hoping that the chamber/barrel alignment will be brought under control.
For not having gotten a Kuhnhausen manual yet, I feel my understanding of how the things work is pretty good. I'm smart enough to not have done anything major with the gun's actions, aside from having them totally apart on a few occasions to clean up some unexplainable grit in the actions that came from the factory guns. Once I finally get the Kuhnhausen manual for the S&W guns, I might be tempted to do the simpler stuff on my own.
Some S&Ws and almost all the older Colts will fail Kuhnhausen's timing test. The Colt with its double pawl hand is especially tricky to get perfect timing, and few will lock up when cocked single action. They will lock up when the trigger is pulled.
IF the gun locks up before the hammer drops, don't worry about it. How do you know? Easy. If the firing pin mark is in the center of the primer, you don't have a problem no matter who says what. If not, you have a serious timing problem.
A range rod really is not for testing timing, it is for testing chamber-bore alignment. If that alignment is off, the gun may not shave lead but will certainly not be accurate with the chambers that are out of alignment. A timing problem can be fixed. There is no way to fix mis-alignment except to have the factory replace the cylinder.
Jim
IF the gun locks up before the hammer drops, don't worry about it. How do you know? Easy. If the firing pin mark is in the center of the primer, you don't have a problem no matter who says what. If not, you have a serious timing problem.
A range rod really is not for testing timing, it is for testing chamber-bore alignment. If that alignment is off, the gun may not shave lead but will certainly not be accurate with the chambers that are out of alignment. A timing problem can be fixed. There is no way to fix mis-alignment except to have the factory replace the cylinder.
Jim
Couldn't there be a misalignment of the chambers with the bore if some idgit at the factory didn't properly install the crane? We're talkin about going down to the thousandths of an inch here where all chambers wind up being just outta that "perfect" alignment by barely a smidge if you throw an alignment rod down the bore.
The bullet likely will automatically align the chamber with the bore, it is a small amount and I don't doubt the bullet auto-aligning the chamber as it enters the forcing cone area. I don't think it's a bad cylinder, a few thousandths extra material put onto the inside surface of the crane though appears that it would make for a perfect alignment chamber/bore alignment. Small enough of a change that no damage to the ejector rod would happen, especially if special attention was given to the front detent.
That's just my opinion after having given the situation a considerable amount of thought. Still, you can bet that I'm gonna get as much valuable information as I can to learn all I can about these things. It's still likely going to go off to be worked on, but can't help but think about some solutions for if I was to go about working on it myself.
The bullet likely will automatically align the chamber with the bore, it is a small amount and I don't doubt the bullet auto-aligning the chamber as it enters the forcing cone area. I don't think it's a bad cylinder, a few thousandths extra material put onto the inside surface of the crane though appears that it would make for a perfect alignment chamber/bore alignment. Small enough of a change that no damage to the ejector rod would happen, especially if special attention was given to the front detent.
That's just my opinion after having given the situation a considerable amount of thought. Still, you can bet that I'm gonna get as much valuable information as I can to learn all I can about these things. It's still likely going to go off to be worked on, but can't help but think about some solutions for if I was to go about working on it myself.