Minimun acceptable barrel cylinder gap?

[KeithH]

I've got a new 640 Pro which has been in for warranty service several times. It went back to S&W for a dead night sight before I even took it home from the dealer. It was returned with a new night sight, a new barrel, a new yoke and scratches EVERYWHERE. Test fired it before sending back again it and was keyholing. Barrel cylinder gap was also crooked, .008 higher on one side than the other. They returned it to me with another new barrel and yoke but did not address the obviously bent frame. Sent it back again and they destroyed it and sent me a new one. The barrel cylinder gap on the new one is a VERY snug .002. I almost feel they did that to spite me. Can it reliably run at .002?

I'm exasperated.

[Half Moon]

I've got a new 640 Pro which has been in for warranty service several times. It went back to S&W for a dead night sight before I even took it home from the dealer. It was returned with a new night sight, a new barrel, a new yoke and scratches EVERYWHERE. Test fired it before sending back again it and was keyholing. Barrel cylinder gap was also crooked, .008 higher on one side than the other. They returned it to me with another new barrel and yoke but did not address the obviously bent frame. Sent it back again and they destroyed it and sent me a new one. The barrel cylinder gap on the new one is a VERY snug .002. I almost feel they did that to spite me. Can it reliably run at .002?

I'm exasperated.

Depends on how clean your ammo is and how much you fire between cleaning. Back when I had Dan Wessons, I experimented a bit with cylinder gaps. .002 sounds good on paper but fouls quickly causing cylinder drag until you clean it. .004 is a good reasonable gap.

[KeithH]

Depends on how clean your ammo is and how much you fire between cleaning. Back when I had Dan Wessons, I experimented a bit with cylinder gaps. .002 sounds good on paper but fouls quickly causing cylinder drag until you clean it. .004 is a good reasonable gap.

My concern is that it will be returned to me with a .010 to .012 gap. I’ve been professional with them and not a jerk but I’ve lost confidence. Seems that the easiest jobs go to the most unskilled people.

[Half Moon]

My concern is that it will be returned to me with a .010 to .012 gap. I’ve been professional with them and not a jerk but I’ve lost confidence. Seems that the easiest jobs go to the most unskilled people.

Heck, they might be thinking they're doing you a solid. The 686 CS1's,some of the Korths, etc all were spec at .002. And I've seen folks brag on custom builds at .002. It does minimize velocity loss at the b/c gap. Personal experience says it's a skosh tight for a practical revolver but may not have been malicious nor incompetent in the doing.

[KeithH]

True. Someone might’ve thought they were being nice to me or doing me a favor. I see your point. I just feel like .002 is a bit tight for a defensive weapon.

[Stephanie B]

True. Someone might’ve thought they were being nice to me or doing me a favor. I see your point. I just feel like .002 is a bit tight for a defensive weapon.

With jacketed ammo and clean powder, it should be fine for defensive use. I can't see most defensive uses for a .38 J-frame going past ten rounds.

Lead SWCs and Unique might be a different story.

[lee n. field]

I've got a new 640 Pro which has been in for warranty service several times. It went back to S&W for a dead night sight before I even took it home from the dealer. It was returned with a new night sight, a new barrel, a new yoke and scratches EVERYWHERE. Test fired it before sending back again it and was keyholing. Barrel cylinder gap was also crooked, .008 higher on one side than the other. They returned it to me with another new barrel and yoke but did not address the obviously bent frame. Sent it back again and they destroyed it and sent me a new one. The barrel cylinder gap on the new one is a VERY snug .002. I almost feel they did that to spite me. Can it reliably run at .002?

I'm exasperated.

My .44 Tracker came back with .003 gap. Still sometimes gets gunked up enough to have trouble turning, shooting my cast lead handloads.

[FrankB]

I’d be tickled to get a revolver with a .002” gap! You can always remove material, but can’t add it. I carry a .006” feeler gauge in my wallet, and won’t buy a revolver that has a larger cylinder gap. I know two Team Ruger shooters, and they want a much larger gap for revolver competition.

[jtcarm]

I have two 66-7s with .003 gaps. A 2.5 and a 4”.

Both run fine.

At a recent range session, the 2.5” digested roughly 150 rounds of cast wadcutters lubed with liquid alox. Smokey stuff. The powder was Clays, which is very clean-burning.

The 4” is the most accurate revolver I own.

It also delivers screamin-fast velocities, courtesy of that tight gap.

[D-der]

After reading this thread, I got curious and checked my 642 Pro that I'd gotten back not long ago with a new frame and barrel after two trips back to S&W, it's .002 as well. I haven't shot it very much since its return, just trying to conserve 38's in case a 642 UC shows up but, maybe 25 -40 WC's at a time with no problem, I do always brush it well when done though. I also pulled my LCR 9 out of my pocket and that's .003, both guns had consistent measurements in all chambers. I've shot the LCR quite a bit with no issues, again I always brush it out when done shooting.