My new to me 28 no dash just started hanging on one chamber, both single and double action. Also, the photo shows the front of cylinder and it's strange pattern on that sticking chamber. I took the side plate off, didn't see anything amiss cycling through the action, put the side plate back on and now it seems fine, but I haven't taken it to the range yet. The loads shot were very light, 125 gr. 3.4g Bullseye.
Anyone have any ideas?
thanks,
Stu

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Cylindr pattern.jpg (46.5 KB, 182 views)

Looking into the light so you can see in the gap, SLOWLY spin the cylinder and watch between the face of the cylinder and the forcing cone. See if one of the cylinders is coming into contact with the forcing cone and rubbing. Used to see it in the old days when the TV types were checking their loads and doing a wrist flick to snap the cylinder shut. It can cause the yoke to bend. I'm not a 'smith so won't talk about repairs, but it shouldn't be difficult.

A 28 only has one cylinder...

With your light loads, and the problem seeming to have resolved itself, it may have been some unburned powder under one part of the extractor star, pushing the cylinder forward on only one chamber. Even so, your gun might benefit from a .002" endshake bushing, to push the cylinder back a smdgen.

Put a feeler gauge between the cylinder and the barrel end (forcing cone).
The "good" 5 chambers take a .009 and fight a .010, the defective chamber barely takes an .008. I wiped it all down and there is a distinct mark that can be felt with a fingernail (.001) on the end of that chamber on the cylinder face. Guess I answered my own question, more or less. Any further thoughts? I could easily stone off the .001 in question to flush the cylinder face. AND, thanks for your thoughts so far.
Stu

It is fine - don't touch it, I think 38 had your answer for you (two post up) take it to the range for a work out. If you have problems come back and they will be given a work out .

Thank you "plug man". It goes to the range tomorrow to see if it will duplicate the symptoms.
Stu

.008" is still quite a lot. Put the stone away! In and of itself, that amount of gap is more than enough. I like about .005"-.006", and there are lots of revolvers out there running fine with .004" and less. However, if you have too much endshake, and I'm betting you do, the cylinder can move forward with firing and fouling, closing the gap to .000". Take Bullseye's advice, and if it hangs up again, there's a good chance that your 28 will benefit from having the endshake taken out.

I had a 28 that didn't run right; same symptoms as yours. Problem was fixed when endshake was corrected. That was on a gun with maybe only 100 rounds total through it. Remember to put some fired cases in the cylinder when measuring for barrel-cylinder gap. Check all 6 chambers.

I did check all 6 and the tight cylinder was the hanger. The other 5 ran .009 on a real tight fit. I'll try again with the cases installed. Also took it to the range yesterday and fired off half a dozen cylinder fulls without a problem. Sometimes yah just scratch your head. I'm going to clamp the gun and measure the end shake with a dial indicator and see what I get.
thanks,
Stu

I have a high round count M28. Twice I've had to replace the bushings for excessive end shake.

If you are looking at cylinder/forcing cone clearance, the problem would be worse when the gun is hot. If the problem occurs during rapid fire more than slow fire, the cylinder may need a thousanth or so taken off - I'd put it in a mill rather than stone it.

If it is a gap problem, it would exist since new. That sort of thing doesn't get worse unless the bushings are shot.

You might also look at the face of the hand, but that end would more likely show up as under-rotation rather than binding.

I'm with the "unburned powder under the star" camp. With .008"-.009" cylinder gap this isn't your problem as that is a pretty big gap (factory specs are .006" IIRC) and my comp guns run .003"-.005". The "unusual wear" your photo shows is actually residue on the last chamber fired, looks perfectly normal.

You could have endshake issues compounding the situation but since you're shooting handloads I'm betting on powder under the star. Also, make sure there is no oil whatsoever under the star as well, one drop of oil mixed with a single flake of unburned powder can shut you down pretty quick. The powder flake acts like a sponge absorbing the oil and swelling up thus causing the star to drag on the recoil shield. Usually feels like only a single chamber is hanging up.

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Non illegitimae carborundum

I agree with MKT. We used to carry 28's as our duty guns for almost 20 twenty years. As an armorer for the agency, the most valued tool I used during qualifications was a tooth brush to keep the powder residue cleanout from under the extractor. Light loads are kind of notorious for this and a little endshake will speed the accumulation process up. Next time you go to the range take a tooth brush and if the gun slows down, give the underside of the extractor and the recess in the cylinder a quick brush. I bet the problem goes away.