.005" cylinder end shake - should I return it?

[Carmady]

This is a NEW LCR, fresh from Ruger CS to replace a different LCR they couldn't repair, which replaced a different LCR...

I measured the barrel/cylinder gap at four charge holes, both with the cylinder forward and rearward.
.008" gap with cylinder rearward
.003" gap with cylinder forward

That's .005" difference, which is WAY out of line with what's acceptable according to a few searches.

Am I being nit-picky, or should I return this one?

[Driftwood Johnson]

Howdy

Curious where you heard that .005 of endshake is "WAY out of line with what's acceptable".

You do realize that a piece of paper is about .004 thick, right?

Has the revolver in question been spitting lead?

Personally, I would say that .005 is at about the acceptable limit of endshake, but I sure would not call it WAY out of line.

Just ran some quick checks on a few old S&W revolvers. Endshake around .003 - .004 for most of them. Of course I have some antiques where the endshake is WAY more than .005. They all shoot just fine.

I suspect if you try to send that one back to Ruger they will tell you it is in spec.

Yes, personally I think you are being nit-picky.

Just my personal opinion.

[Carmady]

Curious where you heard that .005 of endshake is "WAY out of line with what's acceptable".

I often read that there should be 0 end shake during lock up. I read that S&W's limit is .0015", and .005" is over three times that. That's where the "WAY" came from. I have some S&W's which feel like they have no end shake. The LCR which this one replaced felt much tighter than this one. The first time I opened the cylinder there was so much noise I thought I should call it Capt. Crunch.

I called them, the short version is they offered to replace it with my choice of a much more expensive gun at no cost to me, but I declined and said I'll keep the LCR and I'll call them again if necessary.

[ShootistPRS]

Did you check the end play with cartridges in the cylinder?

[T. O'Heir]

"...I often read..." Read where? It matters.
Anyway, 5 thou isn't enough to worry about. In all likelihood, if you send it back Ruger will tell you it's within tolerance and send it back to you at your expense. An LCR isn't a target revolver.

[laytonj1]

"...I often read..." Read where? It matters.

Here's what Grant Cunningham has to say on the issue:
http://www.grantcunningham.com/2007/...e-of-endshake/

Jim

[Carmady]

"...I often read..." Read where? It matters.

I was at home, and sober.

[Carmady]

Here's what Grant Cunningham has to say on the issue:

Thanks! Very good article.

[arquebus357]

Good article but some numbers would have been nice..

[Driftwood Johnson]

I often read that there should be 0 end shake during lock up. I read that S&W's limit is .0015", and .005" is over three times that.

Howdy Again

I have no idea where the OP came up with the figure of .0015 being the 'limit' or that there should be 0 endshake.

I went to my favorite source on all things S&W, Jerry Kuhnhausen's The S&W Revolver, a Shop Manual.

Kuhnhausen only states, as far as S&W revolvers are concerned, that .001 of endshake is ideal. He has no figure for what is the max.

Then I turned to Kuhnhuasen's book on the Single Action Army. In this book, he states ''Whether bushing and base pin diameters are within individual specifications is less important than aggregate cylinder bore/base pin bushing/base pin/frame base pin hole clearance. Original ordnance specifications called for zero perceptible vertical cylinder play and endplay when the cylinder was installed in the frame."

Translation: once everything has been adjusted, there should be zero endshake. Notice he does not specify a maximum allowable amount of endshake in this book either.

Finally, I referred to Kuhnhuasen's book about Ruger Single Action revolvers. (Sorry, I don't have his book on double action revolvers. I only have one, so I never bought that book)

In this one he states that as close to zero endshake is desirable. He also mentions "Cylinder endplay causes variable headspace and variable barrel/cylinder clearance and, when excessive, can also cause the cylinder to thrust rearward and slap seat against the frame ratchet bearing surface on firing. Past a point excessive cylinder endplay can also cause variable ignition and misfires, particularly in revolvers with minimum, or less, firing pin protrusion and /or reduced tension mainsprings".

This statement about the possible injurious affects of endshake would be true with any revolver.

Notice that again in this book he states zero endshake is desirable, and he mentions a few bad things that can happen with excess endshake, but nowhere does he give a figure for what he considers to be maximum allowable endshake.

It should be stated at this point that Kuhnhausen's books are manuals for gunsmiths. Rather than stating maximum allowable amounts of endshake, he covers in detail various ways to fit a number of components, to get endshake down near zero.


-------------------------------------------------


Next, just for the fun of it, I pulled out a few revolvers, just a small sample, and did some measuring.

Let's start with Smiths.

Model 17-3, 22RF, made in 1975, .003 of endshake.
Model 14-3, 38 SP, made in 1974, .002 of endshake.
Triplelock, 44 SP, made in 1915, .003 of endshake.
K-22, 22RF, made in 1935, .005 of endshake.
Model 617, 22 RF, made in 2003, .001 of endshake.
Model 686, 357 Mag, made in 2015, .002 of endshake.

Let's look at a couple of Colts

SAA, 2nd Gen, 45 Colt, made in 1968, .003 of endshake.
SAA, 1st Gen, 38-40, made in 1909, .006 of endshake.


A few Rugers

Blackhawk, 45 Colt, made in 1975, .004 of endshake.
Vaquero, 45 Colt, made in 1993, .004 of endsake.
GP 100, 357 Mag, made in 1997, .002 of endshake.

I noted the dates to show that over time, endshake can increase. However I have no data to show that the frames of any of these guns have actually stretched over time, that they did not leave their respective factories in the condition they are in today. It is interesting to note that the old K-22 has .005 of endshake. I doubt if recoil from 22 rimfire ammo would have stretched the frame.

Also interesting to note is the 2nd Gen SAA with .003 of endshake. When I bought this gun about ten years ago it was my first Colt. I noticed it had some endshake. A gunsmith told me endshake is bad and will increase over time. He was probably referring to what Kuhnhuasen calls 'slap seating'. I can categorically state that after ten years of firing nothing but heavy recoiling 45 Colt Black Powder loads in this Colt, the endshake has not increased. .003 seems pretty acceptable to me. The .006 of endshake in the 1st Gen Colt is pretty excessive, but hey, the gun is almost 110 years old.



--------------------


Is .005 of endshake unacceptable in a brand new Ruger LCR? I really have no idea. Based on my very limited sample, it does seem a bit excessive. I could measure a whole lot more revolvers, but I really don't feel like it right now.

It should also be mentioned that part of Bill Ruger's genius was designing firearms that could be assembled by relatively unskilled assemblers. Not true with the glory days of Colt and S&W. Assemblers in those factories were skilled craftsmen who hand fitted parts to exacting fits. That is exactly what Bill Ruger was trying to avoid, he was trying to drive the cost out of assembling his firearms. So he designed them so they could pretty much be assembled by unskilled assemblers dropping parts in straight out of the parts bins with no fitting. The only way to do that was to increase the tolerances of the parts, so individual fitting was not needed. It follows that with looser tolerances, a certain amount of slop would creep in. My point is, and I will freely admit I have only handled a Ruger LCR once, I would not be surprised if a bit of slop has crept into the LCR assembly line. On the other hand, I was quite surprised to find the GP 100 I own only has .002 of endshake.

[Model12Win]

I'd call the Ruger shop and ask if it's excessive. Good luck getting the little gals that answer the phone to even understand what you're talking about, but hopefully they connect you with a shop tech!

[James K]

Most guns that show end-shake have seen a lot of service. The factory ideal would be close to zero (not zero or the cylinder binds) but in the real world, 2 or three thousandths would be no problem and most guns that have seen any use will show more. Remember, though, that all the recoil of the cylinder is not involved. The cartridge recoils in the chamber and back against the frame; friction will cause the cartridge case to pull the cylinder back with it, but the combination of inertia and any lubrication will prevent the cylinder from going along for the full ride.

Also note that most Colts have a relatively small ratchet tooth, which means that when the cylinder does come back, the ratchet tends to peen the standing breech more than the flatter ratchet typical of S&W revolvers. The S&W ratchet is also made with a larger flat surface in the center, which the Colt does not have, allowing the Colt ratchet to peen the breech more.

Jim

[tangolima]

End shake should be no more than 0.002". I would let it go if it is 0.003" for a light caliber. 0.005" for a brand new revolver is too much.

End shake has little to do with spitting lead; that's cylinder gap. It gives the cylinder a head start to bash on the frame. Little end shake leads to more end shake, and to a lot of end shake. It is the first thing to check and the first thing to fix when a revolver comes in my shop.

-TL

[FrankenMauser]

Both of my recent new Ruger revolver purchases have substantial end-shake, and both went back to Ruger for repair (for other reasons).

The LCR is within their tolerances. (.327 Federal, even, at 45k psi.)
The SP101 is within their tolerances. (.327 Federal, again.)

The LCR went back for timing.
The SP101 went back for timing and a crooked barrel.

They fixed the SP101 by fitting a new cylinder and stealing a barrel from another revolver. (Possibly from a revolver belonging to another member here. )
The LCR paperwork did not specify what they did, but it worked better upon return than before I sent it.


Is 0.005" unacceptable by my standards?
Yes.
Is it unacceptable by Ruger's standards?
Apparently, not.

I stopped worrying, and started shooting.

[Carmady]

Captain Crunch is in a box and on his way back to NH.

[Kreyzhorse]

Curious what was wrong with the other two LCRs?

[Model12Win]

Captain Crunch is in a box and on his way back to NH.

Good call, brother.

[James K]

"...end shake has little to do with spitting lead; that's cylinder gap."

True, but enough end shake results in barrel/cylinder gap as the frame stretches and the cylinder peens the frame. Those things are not separate issues; they are all related.

Jim

[tangolima]

But one could have excessive cylinder gap but no end shake. The revolver is spitting lead but there is no end shake to be fixed.

One could also have too much end shake but the cylinder gap is still in spec. Not to fix the end shake just because it is not spitting lead is unwise.

That's the point I was trying to make.

-TL

[Carmady]

Curious what was wrong with the other two LCRs?

The firing pin bushing on the first one had crept forward enough to block the cartridge rims, which prevented the cylinder from rotating.

The timing was off on the second one. The charge holes wouldn't completely line up with the bore. Lead City.

[Kreyzhorse]

Wow. Either you had a run of bad luck or there must be on going problems with this design.

[straightshooterjake]

Wow. Either you had a run of bad luck or there must be on going problems with this design.

I am not aware of problems with the design of the Ruger LCR revolvers. However, it is very possible that they are having problems with quality control. If the revolvers leave the factory the way they are intended to, then they work fine.

[superspirit]

^^^Ruger no longer has quality control thats the problem^^^
I've had to send 5 back in the last 4 years, I'm not buying any Ruger products anymore!

[James K]

Tangolima is correct, which is why I said that those dimensions are not separate, but inter-related, as is wear and frame stretching (a more common problem than usually thought, especially with guns that have been fired a lot with hot loads).

A related issue that keeps cropping up is the idea of a top break revolver for cartridges like the .357, .44 Magnum, .454, etc. Because there is a need for some play to allow the gun to be opened, that play will allow battering that will eventually ruin the gun a lot sooner than a solid frame revolver. While a break top .454 may seem to be feasible, and even work OK for a while, the inevitable result will be disaster, and a lot sooner than a solid frame revolver.

Jim

[Carmady]

I received the "repaired" replacement LCR yesterday. This was the second new replacement LCR they sent me, and I sent it back on account of the .005" end-shake. At first they weren't going to fix it, but they changed their minds.

The tech replaced the ejector. Now the b/c gap is around .005" (was .008"), and the end-shake is about .001-.002" (was .005"). Those are ballpark measurements instead of precision measurements.

I still haven't shot this one. When I got it I was kinda ticked and parked it on a shelf for a few days, then called, and called again, and sent it back.

Maybe I'm hard to get along with.