Cylinder rotational play

[Narragansett]

How much cylinder rotational play is acceptable? I am not referring to lateral movement, or front to back end shake, but rather turning the cylinder in the cocked or uncocked position as in trying to rotate it left to right.

Is there a point that this becomes dangerous?

If it is excessive, what is the fix, a newly fitted cylinder stop?

 

[chief38]

As long as the Cylinder is locked up fairly tight when the trigger is in its rearward position (as when fired) you should be OK. They make Range Rods to check the alignment of the Cylinder /Barrel - sold at Brownell's, Midway, or any GS should have one. There is always some play in a Cylinder at rest because in order for it to operate correctly, the Cylinder Stop must drop into the notches on the Cylinder without hesitation. If they were very tight and had no "slop" they could potentially not drop in fully. Now that is not to say there should be excess play, but on most S&W Revolvers a little movement in either direction is common and within tolerances. Exactly how much yours has - I obviously do not know from here. Your Cyl Stop could be undersized or Window oversized - but again, can't check that from here. You could post a video so we can see.

 

[armorer951]

Some gauge (small amount) in these components is actually necessary for proper function. This gauge or "play" in the assembly comes initially from fitting the cylinder stop to the smallest stop slot in the cylinder. Since these slots are not always exactly the same size, there is some play or gauge introduced at that interface.

Also, you have the difference between the width (size) of the stop ball, and the width of the stop window in the frame, which adds a bit more movement. (also necessary)

The key is getting the timing set so the cylinder rests at the correct spot when the gun is fully indexed in terms of barrel/cylinder alignment, and is ready to fire. Using a range rod to verify chamber and barrel alignment can help with this critical fitting.

Wear and tear and abuse can, and do take their toll. Fortunately, there are "oversized" parts available, and other corrective measures, like micro-welding, you can employ to address most of these problems, and bring the revolver back into spec.

As usual, Jerry Kuhnhausen has some very interesting information about these specific parts relationships in his shop manual.

Sorry Pete, but I can't actually answer your question definitively. I think you'll know when it feels out of spec by comparing it to your other S&W revolvers.

Carter

 

[Narragansett]

Thanks, just wondering. Something I was looking at in a LGS the other day, just seemed a bit sloppy, but it was a 1948 K38. I checked my own guns, I have everything from some movement to bank vault lockup

 

[Hondo44]

Bank vault lock-up has its problems too and is only a good thing when the chambers are line bored to the barrel with perfect alignment.

On standard production quality revolvers, one must recognize that for the bullet to align the chamber to the barrel using the forcing cone in the barrel as designed, the cyl must have some play!

Also recognize that a range rod will only verify "closeness" to proper chamber-to-barrel alignment. The bore diameter, distance between the lands, is not always the same as the chamber throat diameter. Plus there's some tolerance in the range rod diameter for it to be able to be inserted down the bore. If the range rod will go from barrel to chamber throat without catching on the edge of chamber throat with hammer cocked, that's pretty good. If you have to wiggle the cyl to take advantage of the play you're commenting about, that's okay to, and why the play is needed.

If it doesn't align by moving the cyl and taking up the play, you likely already know about it because the accuracy probably sucks.

 

[oysterer]

Pete, almost a question of Philosophy and I am curious to track the answers here.

Colt: The so called pawl touches the ratchet and lock it up tight. The cylinder must be perfectly lined up for this to work and s.... can get out of alignment and depending who you ask quicker than on a smith.

Smith: They have generally more play and the role of the forcing cone is to line up things as the bullet passes through. The so called hand stays in touch with the ratchet as the hammer is back and trigger fully pulled. There can be a little play or non at all. I do not think no play at all is the spec for a smith. If the hand is not supposed to interact with the ratchet after cycling and hammer back, trigger pulled meaning all the play is dictated by the fitting of the trigger stop alone eludes me...not sure I put this eloquently...

 

[BigBill]

My colt python had a bank vault lock up when the trigger is pulled and held.

My m28 I been working on the cylinder lock is relaxed there is a rotational play, now when the trigger is pulled and held there is a slight play in the lockup. Very little. I still seen revolvers that were still accurate with more play than my m28. While it's not was tight as my python does it matter I don't think so.

I read if we hand fit a over size cylinder loc cam it can jam if it's too tight.

 

[stansdds]

Colt and S&W used very different lock work designs. The Colt is famous for its tight lockup of the cylinder when the trigger is pressed all the way to the rear. S&W's lock work is different and usually does not provide this degree of stability to the cylinder. The S&W lock work is considered to be more durable that that of the Colt, especially when shooting double action. The S&W will develop more cylinder play after a lot of rapid double action use. The cylinder stop can wear, but the cylinder stop notches can also become peened from rapid double action use.