Cylinder End Play--How to Measure and Other Discussion of

[aaaaa]

So, I have some cylinder end play on my S&W .41 Magnum. I measured it to about 0.004" but with a feeler gauge set that only went down to 0.008 and was in 0.002 increments up. Max was 0.012 and some places online say that is acceptable but at the upper end of acceptability for S&W.

One thing I saw online was that end play should be measured with empty cases in the cylinder to simulate the condition of a cartridge in place when firing. In so doing, it seems my end play may be less than stated above.

Tonight I obtained a better feeler gauge set that goes down to 0.0015 and will remeasure end play then post my findings here.

I also see apparently some have had different end play on different chambers in the cylinder. So I guess I should measure for each of the six bores. Too bad their is not a reference mark for the #1 bore or something.

Also, anyone please post your revolver's end play measurements and discussion.

 

[unspellable]

Cylinder gap may vary from chamber due to the cylinder face not being square to the axis. End shake should measure the same for all chambers. I have had excessive end shake on a S&W out of the box. If it's excessive end shake due to wear, pull the cylinder off the yoke and look at the bottom of the well. the yoke tail will wear a groove in the bottom of the well. S&W will correct this by stretching the yoke. This can only be done once. You can correct end shake your self by adding made for the purpose shims at the bottom of the cylinder well, which in my mind is a better fix anyway. Measure with out brass in the chambers. It's very rare that the cylinder will go too far back.. Most of the end shake is from the cylinder going forward. Ideal end shake is 0.0005 to 0.0010 inch. If it gets to 0.003 or 0.004 it's time for a shim. End shake is self promoting, the more you have, the faster it will increase.

 

[dfariswheel]

To measure cylinder end shake..........
Thoroughly clean the frame around the breech face, the rear of the ejector, and the underside of the ejector and it's seat in the cylinder.
Make sure there's no fouling build up on the face of the cylinder or rear of the barrel.

Push the cylinder forward and hold it there as you use the automotive gauge set to measure the barrel-cylinder gap.
Push the cylinder to the rear and hold it there as you measure the gap again.
Subtract one measurement from the other and that's the actual end shake.

NOTE that the measurement with the cylinder to the rear is the actual barrel-cylinder gap.
Ideally it should be from 0.004" to 0.008" with 0.005" considered to be about perfect.
Also note that these days S&W considers a barrel-cylinder gap of 0.012" to be "in spec", and there are reports they'll pass even wider gaps.

Colt revolvers always held end shake to a maximum of 0.003" before the cylinder collar needed to be stretched at the Colt factory using a special hydraulic device.
You CANNOT put washers in the Colt's unless it's an older version with an exterior flange on the cylinder crane shaft.

S&W always had a looser standard for end shake and never seemed to be very clear about how much was too much.
Usually anything over 0.006" OR the cylinder is contacting the rear of the barrel is too much.
Factory repair is to stretch the yoke barrel by one of several methods, or the simplest, installing hardened stainless steel washers with some grease.
The washer/grease method is considered to be a lifetime repair.

 

[aaaaa]

With the new feeler gauges I am getting ~0.010 to ~0.005 so a shim is in order, perhaps a 0.002 + a 0.001. As I turn the cylinder, the bigger gap varies from 0.009 to 0.010, but the smaller gap stays ~0.005.

 

[Dave DeLaurant]

Here's a link for Power Custom endshake shims:

https://www.midwayusa.com/product/1004129454/

 

[aaaaa]

Here's a link for Power Custom endshake shims:

https://www.midwayusa.com/product/1004129454/

I wonder if an 0.002 is enough when my end shake is 0.004-0.005? They don't offer a 0.003 or 0.001 to combine with the 0.002.

 

[Mizar]

One thing I saw online was that end play should be measured with empty cases in the cylinder to simulate the condition of a cartridge in place when firing. In so doing, it seems my end play may be less than stated above.

Endshake is limited between the cylinder's contact with the collar at the front and the ratchet's contact with the frame at the rear - this is not a Nagant revolver... If you got different measurements with empty cases in the cylinder, you either don't measure it right, or you have a much bigger problem that cannot be resolved by simply shimming the collar. And I believe it's the first of the two...

 

[243winxb]

The face of the cylinder may have some high spots, from your measurements? This can be correcting by turning in a lathe.

If no binding between barrel & cylinder, is it a problem? Check headspace.

 

[Rule3]

The accepted measure of end shake amount depends on who you ask and what day of the month, There are many varying measurements out there
What brand, what caliber when the gun was made etc.
Many article's out there!

 

[aaaaa]

Endshake is limited between the cylinder's contact with the collar at the front and the ratchet's contact with the frame at the rear - this is not a Nagant revolver... If you got different measurements with empty cases in the cylinder, you either don't measure it right, or you have a much bigger problem that cannot be resolved by simply shimming the collar. And I believe it's the first of the two...

I think my measurements were bad initially as I did not have the right feeler gauges. It measures the same with and without cartridges now with the new feelers.

 

[aaaaa]

The accepted measure of end shake amount depends on who you ask and what day of the month, There are many varying measurements out there
What brand, what caliber when the gun was made etc.
Many article's out there!

Well if I shoot magnums out of the .41 it is an issue, but I am having some specials made up and they should not be a problem. But I will get the shims for this one.

I have a .44 Magnum SA that also has a lot of end shake. Can't shim a SA I don't think.

Best bet is stick with specials.

My .357 Taurus with the 12-inch barrel is tight though so I can shoot magnums all day in that.

 

[deadeye dick]

FYI Uberti Cattleman .45 Lc I installed a .45 ACP convertible cyl. onto the frame using a fine flat file and.004 feeler guage. Cyl came with a oversize cyl bushing so i had to file it to fit. SLOW AND STEADY did the trick. I guess the same thing would apply to a DA cyl.

 

[__steve__]

After I received my PC 500 from the S&W performance center for barrel replacement and other issues, it came back with an ideal 0.006” gap. However the cylinder would contact the barrel when closing, there was about 0.002-3” of (fwd-aft movement) cyl end play.

The end play I feared would just get worse considering this thing has a diet upwards of 50KPSI but I fixed it with a shim I ordered at Trigger Shims. The 0.002” shim was dropped into the bottom of cyl and fit perfectly. It also provided a cleaner surface for the yoke to rest on and moves more smoothly.

 

[lee n. field]

Here's a link for Power Custom endshake shims:

https://www.midwayusa.com/product/1004129454/

Triggershims dot com has them for more revolvers than I'm seeing for Power Custom.

 

[aaaaa]

Triggershims dot com has them for more revolvers than I'm seeing for Power Custom.

I like it, can get a 4-pack, with two 0.002 and two 0.003 shims.

What about yoke shims. Cylinder shim holds the cylinder back but with a large cylinder gap, a yoke shim would move it forward? But ion my S&W, the yoke does not have any play it it, or does that not matter, you can put them in anyway to move the cylinder forward? That would tighten the cylinder gap? The yoke has about 0.0015 clearance (a 0.002 will fit but a bit too snug) between the yoke and the lug under the barrel, so it looks like at most a 0.001 shim could be added which does not gain much over a 0.10 cylinder gap. Or does one file the small bit of the barrel lug that the yoke fits behind?

 

[aaaaa]

As for my SA Interarms Virginian Dragoon .44 Magnum, I see there is about 0.011 maximum cylinder gap. I have 0.006 (tightly) between the front of the cylinder and the frame at the center pin (so presumably that is my end shake). A shim could be put in front of the cylinder where the pin goes in but there is no way to fasten it on, whereas the Colt can be taken apart to install a shim as shown below.

 

[243winxb]

The gap between barrel & cylinder was huge on the Interarms Virginian Dragoon .44 Magnum, i had. Thought gun blew up on first shot. Huge fire ball, front of cylinder.
Fired 6 shots and sold it.

I would not be making the cylinder gap larger.

You may get better answers posting in gunsmithing.

 

[243winxb]

S&W M29 44mag.
Heavy loads of W296 caused peening (arrow) of the metal around the center pin . This caused the pin to stick inward. Fixed by removing pin and opening hole with the correct size drill bit. Installed new center pin.



Heavy wear in this area from 1000s of max 296 load will change end shake, headspace, I think?
Only fix may be barrel set back, like was done to my M29-2. For headspace, maybe a new cylinder, later?

 

[Mizar]

What about yolk shims. Cylinder shim holds the cylinder back but with a large cylinder gap, a yolk shim would move it forward? But ion my S&W, the yolk does not have any play it it, or does that not matter, you can put them in anyway to move the cylinder forward? That would tighten the cylinder gap?

The yoke (it's "yoke" not "yolk") rests on the frame via the semicircular end of the collar (which is an integral part of the yoke) - this is what limits forward travel of the cylinder & yoke assembly. You can see the indentation on the frame from the contact, just bellow the barrel, on the picture bellow (not my revolver). There should be a small gap between the yoke and the barrel lug, so there is no unnecessary friction and to protect the finish of the yoke. So, unless you have front to back play on the yoke with the cylinder in closed postilion, leave it alone. Not to mention that shimming this area will do nothing to move your cylinder forward and limit the B/C gap.

 

[aaaaa]

The yoke (it's "yoke" not "yolk")

Ya know, in the back of my mind I had it that I need to check the spelling but it was late and I needed to turn in and it slipped my mind. Oh well, that is one spell check will not catch. Going back and fix it now.

Anyway, your advice is just what I needed to not dig deeper into a gun than necessary.

Also found out from the person at triggershims that for a SA that does not have a center pin in the cylinder, people just manage to get the shim in place, or some will glue it on the front of the cylinder.

I think I am all set now, so next task is to order some shims and report back when the job is done.

Thanks, Paul

 

[Mizar]

I don't think that glue will hold with your SA revolver - the bushing takes a constant beating every time a cartridge is fired. Just put the shim there and be careful with disassembly afterwards not to loose it.

 

[aaaaa]

I don't think that glue will hold with your SA revolver - the bushing takes a constant beating every time a cartridge is fired. Just put the shim there and be careful with disassembly afterwards not to loose it.

Yep, its not like I shoot it that much. Really for this one, since there is a nub at the integral hub, (nub at the hub, that has a nice ring to it), a cap washer (something with a short sleeve) would hugely assist assembly.

Probably a thin film of oil or grease would help hold it in place.

 

[__steve__]

Yes, shimming the yoke (at yoke/frame point) forward will not move cylinder forward (won’t close gap) as the cylinder will still rest back to frame under pressure. It will just offset the yoke panel screw.

Also referring to that image with the gap between shroud and yoke/frame, you should see mine, spark plug sized gap lol.
Only aesthetic.

 

[aaaaa]

^ Yikes! 500 Magnum snubby. Gotta hang onto that one--and I mean physically when shooting, but also not to trade or sell it.

 

[stonebuster]

Last week I installed two cylinder shims(.002 & .003) in a Dan Wesson 15-2 revolver to lessen endshake but primarily to see if it would eliminate a light strike issue I had. Shimming did eliminate light strikes and it did open up the B/C gap another .005 making it measure .011. Thankfully, a Dan Wesson b/c gap can be reset back to .006(or anywhere you choose) in a few minutes. I wonder sometimes why more manufacturers don't use the same replaceable barrel system.