Can this be minimized by shimming the inside of the cylinder? I haven't gauged it, but it feels a little excessive and could use a little tightening up.
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Can this be minimized by shimming the inside of the cylinder? I haven't gauged it, but it feels a little excessive and could use a little tightening up.
Possibly. But I haven't checked to see if the Power Custom shims would work. THat would be the easiest solution if they do fit.
I have fixed one or two Enfiield revolvers in my lifetime. What do you mean by end shake? What is end shaking? The cylinder or the barrel on the axis pin and barrel strap?
The cylinder has excessive movement back and forth on the cylinder axle. A rattling sound from this movement is heard when I shake the revolver. It functions fine and even though it is very used, it is one of my favorite revolvers. They just don't make them like that anymore.
I suppose its all down to what you call excesive. As long as it has no slack when you have rounds in the cylinder then I'd be happy. I've just checked 10 of my Enfields and they all have similar amounts of movement back and forth but some require more effort than others to create that movement so I suggest it may somthing else worn, perhaps your cylinder axis pin allows the cylinder to slide back and forth more easily than a new one.
Maybe someone out there has Gun Digest copies around 1960-5. I once read an article explaining very plausibly that a revolver needed a touch of end shake. If I remember clearly (and I hope this can be checked) the argument was on firing that the pawl will first push the cylinder as far forwards as it will go. The case will initially expand to grip the chamber walls, the primer will be pushed back, and then the cartridge base will be pushed back onto the recoil plate. Microseconds later the cylinder will be pushed back, thus shoving the case back into the chamber and recovering some end play so that the cylinder can rotate. If the cylinder has no end play whatsoever, then it cannot move back and the revolver will jam up pretty quickly as powder and lubricant residues get between the back end of the barrel and the front face of the cylinder.
Thinking it through, this seems to imply that if the gap between cartridge base and recoil plate is X thousandths of an inch, then you need a similar amount of end play to make sure that the recoiling cylinder can press the cartridge back into the chamber again. It would explain why my Swiss 1882 revolver, make with watch-like precision and just about zero end play, jams solid after one complete cycle of the cylinder - it is too precise - too closely fitted for the black powder load!
I realize that I might just be talking twaddle, and hope that in that case someone will politely put me right!
Ah, it's cylinder end float that you're on about.............. Here is how we did it. It might not be as you'd all like it to be but here goes. The ONLY thing that matters with the action of the revolver is that it is tight the moment that it is fired. So this is the test that you'll see all Armourers do. Fire off the revolver, regardless of whether it's a Mk1 or 1* or 1**. Allow the hammer to roll forwards under control with your left hand and allow the hammer to drop fully down as if firing a cartridge AND KEEP YOUR RIGHT TRIGGER FINGER FIRMLY SQUEEZED ON THE TRIGGER. NOW is the time to check the cylinder gap, the pokering of the cylinders (rotary side play) and end float of the cylinder that seems to be concerning us. You won't have the pokering gauges or the slip gauges but you will have the best gauges of all.......... sensitive finger tips and eyes. The cylinder should be held firmly between the pawl and cylinder stop AND fully forwards between the pawl and bearing surface at the front of the cylinder spindle.
There............ now you're all Enfield revolver specialists!
I forgot to say, but any end float on the cylinder when it's in its 'loose' position is really academic unless it's totally ridiculous of course. This is because the end float is governed by the cylinder cam engaging in the radial groove on the cylinder sleeve (the bit that slides over the cylinder axis). And as it is deliberately a loose fit to allow the cylinder to be removed and run freely, that's how it's designed
You float, I play.... it's probably a personal attitude thing:madsmile:Quote:
Originally Posted by Peter Laidler
Slip gauges yes, but pokering gauges? Does that go something like "equal your 5 thou and raise you 2 thou"? How about a photo????Quote:
Originally Posted by Peter Laidler
Thanks for the explanation on how to check this Peter. When I check as you explained my cylinder has no movement in any direction. It is as it should be.:)
No movement in any direction Jedd is exactlky as it should be and as I liked to find them. It meant that I had no work to do. I forget the dimension of the slip or head clearance gauge but someone here will remind us all. I have one somewhere but can't be bothered to find it or read up on the EMER.
As for the pokering gauge set, well, it comprised of 6 what looked like precision ground cartridge cases with a hole bored down and through the centre. The next part was a .357" (?) rod that was stepped down about an inch or so from the breech end, You 'fired' the cartridge case - and heaven help you if the examiner heard you 'dry fire' it.............. - and then slid the 'poker' part of the gauge into the barrel while the small diameter part of the gauge slid into the hole in the 'cartridge'. You did this will all of the cylinders. Well....., you sincerely HOPED that it would poker on all cylinders because if it didn't, you were in for a few hours work.
There were two sorts of poker. The early type would slide through and ding against the breech or firing face of the shield while the second, later sort had a knurled end that you could hold onto and wouldn't allow the other end to ding against the firing face.
So there it is..........., the pokering gauge set. the 7 parts came as a matched set...... Heaven only knows why. And there's the answer to anyone who has a few ground 'cartridge cases' and either didn't know what they were for or thought wrongly that they were .38" Enfield CHS GO gauges. Same applies if you have a .357" or so bore gauge with a smaller diameter stepped end. And there's bound to be someone out there with a set!
Next technical question about the trusty old .38" Enfield.............
A very enlightening reply, Peter! The professional version of what I have been doing up to now for old percussion revolvers - i.e. sliding a close fitting rod down the barrel and seeing if it reached the end of the chamber without snagging. If it does not touch the sides of the chamber, then the next refinement is to see if the cylinder can be revolved equal amounts clockwise and anticlockwise. Yes, it's a quick and dirty method, but suffices to distinguish between "hopeful" and "hopeless" cases.
Not that I measure end shake on much of anything besides S&W revolvers, but on these the cylinder float can be controlled by adding "O" shaped shims between the end of the yoke ("crane" to Colt types) and the cylinder ID. I will often set it to 0.002" on general purpose Smiths and 0.001" on hunting and target S&Ws if everything else is running true. I run many of these revolvers fast and dirty. No dramas to date. My old 686 .357 has had multi tens of thousands of rounds through it. End shake is still tight, but that's about the only thing!Quote:
Originally Posted by Patrick Chadwick
The usual binding drama on Smiths is when the cylinder drags against the rear face of the barrel, which the shims will cure straight away.
As for the Enfield revolver, it never occurred to me that the forward motion of the Enfield's cylinder would be controlled by anything other than cylinder axis' rear face (which shimming would change, if so.) or the front of the cylinder sleeve which is very "beefy". But I've never had a binding drama with one, nor headspace so excessive that misfires occurred. So it's been of no concern until now! Given the low pressure of the round, binding due to cartridge set-back seems highly unlikely.
Quote:
Originally Posted by jmoore
Now I wish I'd bought that copy of Gun Digest when I had the chance. It made sense when I read it, now I'm not so sure. But if a revolver cartrdge is very lightly loaded, then surely the case will expand poorly and not grip the chamber wall (indicated by powder residue on the outside of the case) and thus the whole case could be shoved back while the bullet is moving forwards but has not yet left the chamber mouth. When the cylinder is pushed forwards on firing, the clearance between the back of the cylinder and the recoil plate must surely produce similar effects to those in a rifle with a large headspace???
Yes, but the case doesn't grip the chamber walls afterwards. It will be driven forward by the firing pin when the pressure falls.
Also note that the rearward motion of the case often partially recocks the hammer, so there's a secondary hit in many cases. Never noticed by the shooter!
( I have a Model 547 S&W that has a case driving pin above the firing pin. The impact of the 9mm case against this pin is sufficient to
drive the hammer to full cock! With the trigger stop i have on this revolver, it would sometimes be fired but the hammer would appear to have never fallen! Weird. But not hard to sort, so now it doesn't do that anymore.)
https://www.milsurps.com/images/impo...0032c34a-1.jpg
Breech face of the 547. Note the "case reseating pin" above the firing pin. Needed with the high pressure 9x19 tapered walled cartridge.
Note that if the firing pin hole is too big, there is a small chance that the primer may flow into the clearance enough to lock things up. But I'd guess it's a very remote possiblity with the .380/200 AKA .38 S&W.
BTW, I have some Gun Digests from that period. Any clue which one?