In order to participate in the GunBroker Member forums, you must be logged in with your GunBroker.com account. Click the sign-in button at the top right of the forums page to get connected.

cimarron open-top cylinder creep

dsmc1dsmc1 Member Posts: 112 ✭✭
edited July 2013 in Ask the Experts
Recently I purchased a used, but apparently unfired, open-top in 38 cal. When the hammer is pulled back to full cock, the cylinder locks up perfectly and solidly. However, as soon as I begin to lower the hammer, the cylinder creeps back 1/16-1/8 inch.
I would assume the Hand is dragging on the back of the cylinder as it retracts with the downward motion of the hammer, but that should NOT cause a problem if the cylinder stop were still fully locked onto the cylinder notches.
I removed the cylinder, cocked and lowered the hammer, and cannot SEE any movement in the cylinder stop, but assume that it MUST be retracting just enough to weaken the contact with the cylinder notch, allowing the cylinder to creep.
I tried disassembling the revolver, and lightly polishing the bevels on the ear of the cylinder stop and the hammer lug that engages it, as well as the front of the hand (to remove any possible burrs) but that did not help.
Stop spring seems fine.
Have rebuilt several SAA's and Colt percussions and never had this problem.
Would welcome any suggestions.
I thought about polishing the body of the cylinder stop in front of the lug, to allow it to extend further thru the frame and fall deeper into the cylinder notched, but don't think that is the best direction to go.
Thanks.
· Share on FacebookShare on Twitter

Comments

  • rufe-snowrufe-snow Member Posts: 18,650 ✭✭✭
    edited November -1
    Personally I only could see a problem. If repeated shots after the first were out of time, i.e the cylinder didn't lock up when the hammer is brought back to full cock.

    The quality of the Italian cap & ball repos, which I assume you have. Has always been iffy as far as workmanship and materials are concerned. I wouldn't sweat it as long as it's in time and all 5/6? chambers lock up.

    EDIT #1, Te only way the cylinder can move as you describe, is if the locking bolt is disengaging. There is a leaf tensioning spring in the frame that engages the locking bolt. It's not doing it's job,as designed. Either try bending it or shimming the spring, for more tension on the locking bolt. For all you know the spring and/or the locking bolt itself is out of spec. As I noted previously the workmanship and parts of some of the Italian made replicas, leave a lot to be desired.
    · Share on FacebookShare on Twitter
  • dsmc1dsmc1 Member Posts: 112 ✭✭
    edited November -1
    Thanks for the reply Rufe, but with the cylinder creeping (rotating) backwards up to 1/8 inch as the hammer falls, that would be 1/3 of the diameter of the bullet that likely will shave off, jamming and possibly damaging the revolver. (or damaging ME!)
    Not sure I'm eager to try putting a shot thru it to see if it locks up on a second cocking of the hammer.
    Note this is an Italian Cartridge model,38 Colt or 38 Special, not cap and ball,
    · Share on FacebookShare on Twitter
  • TRAP55TRAP55 Member Posts: 8,292 ✭✭✭
    edited November -1
    At full cock, if you can rotate the cyl by hand, the bolt isn't into the cyl notch deep enough. Cyl endshake (forward and back movement) can cause this too.
    If the hand spring has enough tension, and the cyl pin fit is loose, the cyl rides up and forward. That has the bolt sitting on the rear edge of the cyl notch, and not locking.
    That's my best guess with having it in hand.[:)]
    Is the bolt/trigger spring flat steel or wire?
    · Share on FacebookShare on Twitter
  • dsmc1dsmc1 Member Posts: 112 ✭✭
    edited November -1
    Rufe-Snow said; EDIT #1, Te only way the cylinder can move as you describe, is if the locking bolt is disengaging. There is a leaf tensioning spring in the frame that engages the locking bolt. It's not doing it's job,as designed. Either try bending it or shimming the spring, for more tension on the locking bolt. For all you know the spring and/or the locking bolt itself is out of spec. As I noted previously the workmanship and parts of some of the Italian made replicas, leave a lot to be desired.
    Will check the spring tension. Had considered that as part of the issue, but figured it was OK since it does lock up at full cock.
    Thanks for the idea. MAy NOT BE STIFF ENOUGH TO HOLD THE BOLT IN THE NOTCH AGAINST THE BACK DRAG OF THE LUG.
    Will post results
    · Share on FacebookShare on Twitter
  • dsmc1dsmc1 Member Posts: 112 ✭✭
    edited November -1
    Finally resolved the problem. The cylinder stop was not dropping into the cylinder notched deep enough to keep it from rotating backward, when the hand was dragging it that direction when the hammer was lowered.It would lock against the deeper side of the notch, but on the leading edge, where there is a depression cut to allow the stop (bolt) to drop in gradually, there was not enough of an edge for the bolt to catch. It also would not lock up with the hammer down.
    It was NOT technically locking tight at full cock: it was locking against only ONE side of the cylinder notch, and was being held there by the hand. As soon as the hammer lowered and the hand began to retract, it would drag the cylinder backwards more than an eighth of an inch.
    I replaced the cylinder stop and it now locks up perfectly.
    Thanks again for all the brainstorming and ideas, that lead me in the right direction.
    · Share on FacebookShare on Twitter
Sign In or Register to comment.