View Full Version : Jammed Cylinder
January 8, 2011, 11:01 AM
This is a follow up on a prior thread. I have a SAA 45 Colt that after a few shots the cylinder tends to jam. I can't figure out what is causing this- its not backed out primers. It's not a rough cylinder shield- it's polished smooth. I replaced the cylinder pin bushing and maybe it's too tight but I don't want to stone it down if that's not the problem- the gap seems ok.
In any event when I start to cock the hammer and the hand starts to rotate the cylinder- the hand pushes the cylinder forward and the bushing is in contact with the frame. Is that normal?
Any suggestions welcomed. Thanks.
January 8, 2011, 12:07 PM
Yes the bushing should be in contact with the frame when the cylinder is rotating. You say this happens only after a few shots have been fired. You didn't mention what loads you are shooting. If they are blackpowder and you have a very close fit to the frame/cylinder bushing the cylinder can heat up enough to expand and jam things up. Easy check for this is when it starts to bind up let it cool for a few minutes and check. Ideally you should have about .002 to .004 frame to bushing clearance.
January 8, 2011, 03:18 PM
Ideally you should have about .002 to .004 frame to bushing clearance
Not enough for bp. I'd want at least .006-.008 altho I have run them at .004. Anything less is asking for trouble.
January 8, 2011, 03:51 PM
Hawg, I think you are talking about cylinder to barrel clearance. Denster was talking about bushing to frame clearance.
January 8, 2011, 04:02 PM
Yep, he said it plain as day and I still misread it. :D
January 9, 2011, 01:11 AM
In addition to fouling, too little b-c gap can cause the cylinder to hang up when it expands from heat.
The bushing should contact the frame before the cylinder can contact the barrel. The bushing, combined with the ratchet, controls the b-c gap and headspace.
January 11, 2011, 01:38 PM
I'm not a BP shooter (yet :D), but one of the things I've picked up from some BP shooters that I'm gleaning info from is that sometimes the caps disintegrate and pieces fall down in front of the cylinder face. I note that you state that the caps are not "backed out," but that's not exactly the same thing (unless I just missed it). If I remember my conversation with my BP guru, the solution was to change cap brands, but I'm sure somebody else with a lot more smarts in this area will chime in.
January 11, 2011, 01:53 PM
Good point, Tanker6, but the firearm in question is a single action army, a centerfire revolver, not cap and ball.
January 11, 2011, 01:58 PM
Ok, I'll go back to my hole now. I've been reading multiple threads and my "sometimers" took over.
As Rosanne Rosannadanna used to say, "Nevermind." :D
January 13, 2011, 12:20 PM
Well from what has been said I'm now thinking it must be that the cylinder is heating up and that has caused the metal to expand just enough to cause the problem. I love black powder and shoot both cap and ball and 45Colt. On the 45Colt I use smokeless powder so I don't think it is fouling. Next time out I'll put the revolver aside and let it cool and see if that cures the problem- if so then I'll stone down the bushing a little more. If I do stone it down, I've been "eyeballing it" but I was wondering if some sort of jig would do a better job or maybe pipe grinding compound in the gun itself. Any tips appreciated.
When I installed the new bushing (they come oversized)-I thought the tighter the fit the better, so I am pretty sure I didn't stone it down enough.
January 13, 2011, 02:14 PM
If you have a drill press just chuck the bushing in the chuck and put a piece of medium grit paper on the table. Run the drill about 600rpm and lower the bushing onto the paper. Careful though as it only takes a touch to remove .001.
January 13, 2011, 06:30 PM
Thanks- good idea.
February 27, 2011, 12:21 AM
Mark the cylinder where it locks up to see if it's the same one. I had that happen on an 1860. It turned out that after I removed the nipples and cleaned the threads, one nipple was a tiny bit extended and caused the hammer not to fall completely. That locked up the action.
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