Question about cylinder lock up test

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freebird72

New member
I have read the "Revolver Checkout" sticky several times. However, I am confused on the cylinder lock test. I have done what it says, but every DA revolver(Maybe 50 or more) I have tried it on has had some play; except one. Most had some from side to side, and from back to front. I have tried many different revolvers; new and used. However, I have tried it on a used S&W 19-2. There is zero movement; and when I say zero, I mean no movement anywhere.:eek:

Do most revolvers have some play in cylinder during lock up and the S&W 19 is just a super freak? Or is something wrong with the S&W 19? Am I doing something wrong?

Any info would be really helpful.
 
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They all have some play due to manufacturing tolerance stacking and wear over time. This is why they have a forcing cone, so that the bullet can "self align" itself with the bore when fired. It is normal. And as you have seen, sometimes all the parts actually do fit properly. But that doesn't happen very often.
 
Even in a very tight action like the Model 19 you saw there's enough backlash built into the action to allow the cylinder to move enough to align itself with the bore.
While it may seem to be very tightly locked, it can still move when fired, as it was designed to do.

The only modern DA revolvers that really do lock up with true zero movement are the Colt's like the Python and Detective Special types.

The critical movement in a revolver is to have a minimum of back and forth movement of the closed cylinder, known as "cylinder end shake".
The less of that you have the better, and the factories have specifications as to how much is allowable.
There is no factory spec on rotational movement,.
 
Right. Think of endshake as creating a "battering ram effect" as the cylinder bounces between the back of the barrel (although usually doesn't actually hit there!) and the rear of the frame. This isn't good. Over time it stretches the frame and causes other problems in the action parts.

How bad this is depends on the gun. For example, you sometimes see fairly large guns in .22LR - Colt Officer's Match .22, Colt SAA in .22, stuff like that. In that event the battering ram effect will be driven by only mouse-grade power levels.

In a large-frame gun, 38Spl might be in the same boat - not something you want but still shootable for a good while, possibly forever (S&W N-frame 38 for example).

But step the power up, esp. to 357 or beyond and yeah, it's a problem. In an aluminum-frame gun, BIG problem in .38 and bad even in .22 - they can't cope with endshake very well at all.

Most of the guns you tested had some serious wear.

The cure is to use shims on the cylinder's "axle" to eliminate the front-back motion. As long as you catch it early enough it's no big deal.

That S&W 19 is likely hand-tuned by somebody. Which can be very good. What I'd do next is pay very careful attention to the alignment between barrel and cylinder bores, checking them all. IF they're good in the "hard locked" position, great, you have a very nice critter.
 
The "checkout" and Dfariswheel's post are realistic in saying that most revolvers have some cylinder play, but some folks who post on the subject insist that there should be absolutely NO PLAY whatsoever in a revolver cylinder, else the gun is highly dangerous and needs to be rebuilt or scrapped. One "expert" said that all S&W's are junk and that he would never own one.

What nonsense!

Jim
 
Some of the guns I tested, all .357s by the way, were new. I tried new GP100s, S&W 686s and 586s. The had side to side movement, and a little front to back. So this seems as if they are bad.

On a side note, is the S&W 19 I looked at some kind of rare find? Or are most well taken care of S&W 19s like that? They are asking $500 for the gun, it is nickle and seems in really good condition.
 
Well...a tiny fractional amount of endplay is all too common but not desirable :(.

The 19 with a totally rigid cylinder was indeed a rarity. I suspect it had been hand-tuned by somebody.

Remember, a lot of guns get sold after the owner died, by their family. Sometimes a gun will be a "personal special" that had been seriously re-worked but only the now-dead dude knew to what extent and by whom.

There's a fair number of such pieces floating around.
 
When you say "a litttle front to back" movement, what exactly does a little mean? Anything more than just barely perceptible endshake is something that should really recieve the attention of a gunsmith. As has been mentioned though, with the exception of the "old" Colt DA action, rotational play isn't a problem so long as it's not excessive.
 
Well I am not sure how to describe it. From everything I have read, it would seem there should be no endshake but I can feel it move back and forth and side to side. The only gun that does not does this, and I have tested over 50 DA revolvers(both new and used), is a nickel S&W 19-2. This thing will not move at all. Nothing, no movement what so ever. It is a vault.

I would buy said 19($500), but I have heard too many stories of them not handling a lot of .357 use. If I could find a Ruger GP or a S&W 586 with that tight of a lock up I would buy it in a heartbeat; but with that said I am shy of buying a S&W 19.


Maybe I am doing something wrong during my testing? What I do is, pull back the hammer, then I let the hammer down with my thumb as I pull the trigger with my index finger. With my finger still on the trigger I then do the lock test. Am I missing something?
 
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freebird72 said:
Maybe I am doing something wrong during my testing? What I do is, pull back the hammer, then I let the hammer down with my thumb as I pull the trigger with my index finger. With my finger still on the trigger I then do the lock test. Am I missing something?
Click to expand...

S&W's should be checked with the hammer @ full cock, period (for each chamber/position).

Colt's should be checked with the trigger held in the pulled-back position & the hammer down in fired position (for each chamber/position).

.
 
as long as you're holding the trigger down - as you lower the hammer...and keep the trigger pulled - then do the lock test, you're doing it right....

The model 19-2 in Nickel is a really good buy at $500....none of the model 19's will show any wear from shooting .357 mag loads as long as you're shooting the traditional bullet weight of 158 gr. My model 19's have thousands or rounds thru them - with 158gr bullets...with no issues.

This is often discussed on here ...and often misunderstood / as a persistent rumor. The reported problems on mod 19's shooting .357 mag loads comes when shooters want to shoot bullets thru them like the 125 gr ...vs the more traditional 158gr.
 
First, the Model 19 (Combat Magnum) was designed and intended to give law enforcement officers a compact, lightweight carry gun with enough power for about any crime situation. It was designed and intended for use with the .357 factory ammunition of the day, not for long term use with the heavy charges and jacketed bullets used today, let alone with heavy handloads.

The major problem with the Model 19 firing .357 was that hot loads broke out the bottom of the forcing cone. The reason is simple if you compare a Model 19 K frame to a Model 27 N frame. The geometry of the smaller frame means that the distance from the center of the bore to the center of the cylinder requires that the forcing cone area of the barrel be thinner than if the frame were larger and more space was available.

The problem was never extensive or all inclusive, nor was it caused by .357 pressures as such, but rather by firing large numbers of hard jacketed bullets at high velocity, something the Model 19 was never intended to do.

Jim
 
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