Question about turn marks on cylinders


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moewadle
November 4, 2006, 11:04 PM
I stopped at a table at a gun show recently. This particular man sold me a revolver previously so sort of knew my taste is older stuff. (He does not have lots of guns because he is not an FFL and sharpens knives at gun shows. I mention this because it may be a clue to his level of knowledge, or not.) This date he showed me a pretty old Single Six with quite a bit of wear. However, he said the Magnum cylinder must have never been used because it had no turn marks on the external surface. I looked at the Magnum cylinder and could see lots of turn marks on the "ratchet teeth" (my terminology may be wrong) on the back of the cylinder and there were more turn marks, or whatever, on the rim of the pin opening at the front of the cylinder. I told him that I thought the cylinder had definitely been turned in the gun because of the wear on front and back. He said that since there were no turn marks on the external surface he disagreed with me.
Now, I am into revolvers for only about 7 months. I have a Colt Peacemaker .22 that I have shot perhaps 200 rounds through, a Heritage Rough Rider .22 perhaps 500 rounds or less, a Ruger New Vaquero in stainless perhaps 500 rounds, and a Navy Arms Scout in 38 special (think Stallion) only 50 rounds and I do not think there is much in the way of external turn marks on any of these guns yet.

So, (sorry for rambling) someone explain or expound about the turn marks on revolver cylinders and why they occur and, how long does it take for turn marks to appear on a cylinder????? Am I most likely right or is he....I don't get any kick out of proving people wrong. I am just interested in increasing my level of knowledge and ability to assess wear indications on firearms.

Thanks in advance for a clear explanation.:confused:

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SaxonPig
November 4, 2006, 11:26 PM
The turn mark is caused by the cylinder stop dragging on the surface of the cylinder as it turns. It is possible to have these parts timed so well that little or no mark is made, with the stop not contacting the cylinder between the notches (this is how it should work, BTW). The deeper and more obvious the turn mark the worse the timing and fitting of these parts.

Generally speaking guns were better fitted "back in the day." As I write this I am looking at a S&W Registered Magnum sold in 1938 and reblued by S&W in 1954. After 50+ years (ex-cop gun so much use) the turn line is barely perceptable. These guns were finely tuned and fitted.

On the other hand I have a Model 25-2 from 1980 with the most horrendous turn line I've ever seen. There is an actual groove running around the cylinder. Terrible fitting and timing.

It's not impossible that the auxillary cylinder for that Ruger was fitted so well that it isn't leaving a turn line... yet. It may start at any time.

moewadle
November 4, 2006, 11:39 PM
to share....the manual for my Ruger New Vaq instructs that if the user wants to prevent turn marks the user should position the cylinder so that one flute is placed just adjacent to each side of the top frame before closing the loading gate, which of course is how the cylinder is locked on this revolver.

Old Fuff
November 5, 2006, 10:36 AM
A lot of people misunderstand about what those lines mean.

A properly timed S&W revolver will release the cylinder stop about half way to the next notch. Over time this will leave a line that many don't like, but it's there for a reason. In fast double-action shooting the cylinder stop acts as a brake to slow the rapidly turning cylinder so that the cylinder stop won't skip a notch. It is possible that the cylinder can turn so fast under its own momentum that it is actually ahead of the hand.

Colt and Ruger revolvers have a longer leed going up to the notch, and are timed to release the cylinder stop (aka "bolt") as it comes up to the leed. Thus any mark or ring should be in the leed. The leed on S&W revolvers is much shorter.

Also, if you close the cylinder between notches and then hand-rotate the cylinder to the next chamber, you will in time leave a mark. The only way to avoid these marks is to not rotate the cylinder at all. This only makes sense when it comes to certain safe queens and collectables.

ETXhiker
November 5, 2006, 01:32 PM
Thanks, Old Fuff. Best info I've seen on the subject.

fiVe
November 5, 2006, 04:17 PM
Mucho good info here.

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