Cylinder Gap

hogfish · 02-07-2011, 04:43

Hi, again. After closer inspection, I found that cylinder gap on my 58 varies between an almost snug .003 to a loose .004, and am wondering what your opinions are on this. Is it common, rare, bad, terrible? Do I need to send it to the factory for a tune-up?

Thanks.

**pennlineman** · 02-07-2011, 05:05

The old standard in cylinder gap was .008. Recently I heard as much as .010 is ok. The cylinder should be pushed to the rear when you check this. So your revolver is fine in this aspect. The axis of the cylinder may be off due to play, maybe even a slightly bent extractor rod. Provided the gun shoots well and doesn't spit lead or show major erosion on part of the forcing cone. I wouldn't worry about it. A S&W has to have some play (not excessive) in it otherwise it wouild be so tight that it would bind up.

hogfish · 02-07-2011, 15:46

Sounds like it's acceptable, then. Thank you.

rod727 · 02-07-2011, 17:18

I would be very happy with those numbers. By comparison the Dan Wesson 357 revolvers were shipped with .006 feeler gauge to adjust barrel to cylinder gap but most people gap them between .003 and .006 as an acceptable range.

hogfish · 02-08-2011, 04:09

Quote:

Originally Posted by rod727

I would be very happy with those numbers. By comparison the Dan Wesson 357 revolvers were shipped with .006 feeler gauge to adjust barrel to cylinder gap but most people gap them between .003 and .006 as an acceptable range.

I was more worried about the +.001 difference between tightest to loosest. I read that anything below .003 cylinder gap is not recomended because fouling will tend to close the gap and tighten/stop rotation.

Thanks.

***G33*** · 02-08-2011, 07:02

Quote:

Originally Posted by hogfish

I was more worried about the +.001 difference between tightest to loosest. I read that anything below .003 cylinder gap is not recomended because fouling will tend to close the gap and tighten/stop rotation.

Thanks.

Yes, and you should be OK.

Make sure ejector rod is tight.
Left to tighten!

Clean well under ejector star.
Love 58s and 57s.

hogfish · 02-08-2011, 16:07

Quote:

Originally Posted by G33

Yes, and you should be OK.

Make sure ejector rod is tight.
Left to tighten!

Clean well under ejector star.
Love 58s and 57s.

I would have never guessed that the ejector rod could be loose...and it sure was, but did not seem to affect cylinder gap in this case. I'm putting together an order to include the AGI S&W Armorer's DVD, so I hope to pretty soon be able to know (at least) the basics.

Thak you.

fastbolt · 02-12-2011, 16:12

In the S&W revolver armorer class I took we were told that .004" - .010" is acceptable for the cylinder/barrel gap. It's checked coming in from the left side (frame side) at the top of the frame window.

A loose rod can cause cylinder bind, poor extraction & difficulty in opening.

Headspace is different between the old & new style models (because of the old style having recessed charge holes).

hogfish · 02-12-2011, 17:33

Quote:

Originally Posted by fastbolt

In the S&W revolver armorer class I took we were told that .004" - .010" is acceptable for the cylinder/barrel gap. It's checked coming in from the left side (frame side) at the top of the frame window.

A loose rod can cause cylinder bind, poor extraction & difficulty in opening.

Headspace is different between the old & new style models (because of the old style having recessed charge holes).

I was checking from the right(starboard?) side as I was holding with the barrel pointing away from me, which seems contrary to what you're saying, correct? It should be checked from the side the wheel comes out to?

Thanks.

fastbolt · 02-12-2011, 17:53

Checked from the gun's left side ... also meaning the left side as you're holding the EMPTY gun by the grip, pointing the muzzle away from you. Another way would be to say the left side is the side on which the cylinder opens and closes.

hogfish · 02-13-2011, 08:12

Hmmm...Things are a little different, now that I checked from the left side. Cylinder gap is more uniform, but it is up to where I can get the .007 gauge leaf partly in

. I guess this isn't bad, but I can't help being a bit disapointed, since I originally thought it was half that.

Thanks.

fastbolt · 02-13-2011, 13:04

Well, I'd be inclined to think that .006"+ "isn't bad", too (since you can't get the .007" gage all the way in). It's closer to the minimum .004" tolerance than the .010" tolerance. Probably more tolerant of lead SWC loads, too, regarding lead buildup.