Barrel to Cylinder Spacing... 1858

[Son of Sam]

Hello, all.

I've recently purchased a Pietta Remington 1858 repro from Cabelas but haven't had a chance to shoot it yet. The cylinder to barrel distance is so very close, and I'm wondering if this is normal or not (this is my first BP revolver). As of right now I can't even slip the corner of a piece of printer paper in between the two of them. I have two spare cylinders for it and they all fit like that.

All cylinders spin freely at half-cock and lock up tight with good timing.

Is this good/bad/normal spacing, though? Do I need to remove some material from the barrel at the forcing cone to reduce chance of cylinder lock up from fouling?

I could just shoot it and see for myself how she does when my caps arrive (and I will), but thought I might ask you fine gentlemen (and ladies) what is the norm.

Thanks in advance for any help or replies.

P.S. I don't have any sort of feeler gauges or anything so replying in terms of "piece of paper", "playing card", ect. would be most helpful to me.

 

[Old Fuff]

Your paper shim is probably around .003" to .005" thick. Be sure you pull the cylinder all of the way backwards and hold it before you try to check the gap with your shim. If the hand is pushing the cylinder forward you'll get a bad reading. However do not remove any metal until you are absolutely sure it's necessary. If the balls are lubricated you should get at least 18 to 24 shots before any binding occurs, if then.

 

[Azrael256]

I don't have any sort of feeler gauges or anything

Auto parts store. I paid $1 for mine.

 

[Son of Sam]

Hey, thanks for the replies, guys.

You can't really notice any forward/backward play in the cylinder by trying to move it, but it's there. I did as Old Fuff suggested and when I apply pressure on the cylinder towards the rear of the revolver... a piece of paper slides through nicely. I'm not at all worried about it so much.

Caps will be on the way tommorrow so I'll be out shooting her just as soon as they arrive. Had to mail order them since nobody keeps them in stock around here. Go figure. Most places I've called tell me they're a seasonal item and deer season's over, like I'm a moron for even asking... I must be the only one in my neck of the woods who doesn't look at anything BP related as a deer season extension.

Haven't had a chance to swing by an auto parts store yet, Azrael, but thanks for the tip. For a buck I really can't afford to NOT have a set, right?

Thank you both.

 

[Mad Turner]

Barrel cylinder spacing

Son of Sam by boy I had a similar kind of thing where my 1851 Colt 44 Pietta seemed OK as I had already shot it that day but when it was all loaded and capped and ready to go it became locked up solid. I looked at it and thought 'I wonder what is wrong'. I tried turning the cylinder but it was solid. I decided that perhaps I had driven the wedge in to tight and that the barrel was jammed against the cylinder so I tapped out the wedge and took off the barrel ('they walk among us and they vote' do I hear you say?). However, there I am with a revolver which is still locked solid so I try to turn the cylinder and at the same time trying to ease the hammer when suddenly it all came free and the hammer went down and the thing went off. I did not have my hand in front of the cylinder but shooting a gun without a barrel and your hand that close is not to be recommended. This is England and the police are very fussy about gun shot wounds even when you shoot yourself. Shooting yourself in the foot is one thing, but shooting yourself in the hand is an embarrassment never to be lived down. When I got it on the workbench I found some tiny pieces of cap in the mechanism.

Mad Turner

 

[DaveP (UK)]

Hi! Quite satisfying to be able offer a contribution rather than a request for help as my first post!

Its not that I could claim to be an expert but I was told, at about the same time I bought my 1858, that a small cylinder to muzzle clearance probably helped to reduce the amount of fouling being dispensed from the front of the cylinder. This makes a sort of sense to me, and a small gap seems like a good idea for other reasons as well!
There should be no need to worry about the front of the cylinder binding on the cone - if you think about it the cylinder face tends to get wiped every time you reload! Whenever I've shot mine until it started to bind the problems were caused by thickening of the lubricant on the base pin. Wiping this over and relubing was all that was required to keep shooting.

If the cylinder clearance is small you do have to take great care never to leave a ball sitting proud. The number of times I've had to drop out a part loaded cylinder and start shaving lead, and then remember which one to fire straight into the sand...

 

[pohill]

Mad Turner, when I read your story about shooting the gun without the barrel, it made me think that maybe Paul Revere could have taken his time...

I'm kidding, I'm kidding...

 

[Jim K]

In modern revolvers, a barrel/cylinder gap of about .007" to .010" is considered about ideal. But in BP revolvers, that is really too tight, and fouling will soon build up and stop the gun. I would suggest .010" as a minimum with a maximum up to .020".

Note that for cartridge guns used in CAS, a too tight b/c gap will hang up the gun when it gets hot and the cylinder expands lengthwise. That problem usually doesn't occur with BP guns because they cool down while reloading.

Jim

 

[unspellable]

cylinder expansion

I'm a little dubious about the cylinder expansion thing. I shoot Dan Wesson SuperMags (Sorry to drag smokeless into a BP forum.) and they have a nominal (factory spec) gap of 0.003 inch. Never had any problems. If I remember right the Freedom Arms revolvers also have a tight gap.

 

[Old Fuff]

Back when most revolver ammunition was loaded with soft lead bullets, barrel/cylinder gaps were fairly wide (.006" - .0010") by current standards because of lead splatter on the cylinder face and back of the barrel. As jacketed hollow-points become more common the standard gap sometimes got tighter (.003" .006") which didn't always work because I've seen some that have bound up - especially when using lead bullets. For this reason I usually perfer a gap of at least .006" even when using jacketed bullets.

Black powder revolvers add powder residue to lead splatter, and tight gaps can be a mistake. Jim's minimum of .010" is right on target. Wide gaps don't cause side-spitting unless the chamber isn't concentric with the bore, and I am not concerned with the very little velocity loss.

 

[sundance44s]

Break her in ..

That cylinder to forceing cone gap will widen in a few hundred shots ...enjoy it and use a little extra lube over the balls for a while ...With the Remmies things only get better with age .....I`ve shot mine so much i now only lube over every other ball , and can shoot all day this way .

 

[unspellable]

gap

It seems to me that cylinder gaps on smokeless guns, S&W in particular, have been getting bigger. S&W's factory spec is up to 0.010 inch and it used to be less than that. I ran some experiments with Dan Wesson with adjustable gaps and at 0.012 the gap will start spitting crap even with jacketed bullets. I would say 0.006 is the right value on a smokeless revolver for general sale. Revolvers for BP might run 0.008 and be happy. I've never had a BP revolver hang up because of crud in the cylinder gap, but there's always a first time.

 

[DaveP (UK)]

Fired by the thirst for truth I decided to measure the gap on my own Uberti Remington. Feeler gauges in hand I dragged my protesting bones up to the attic
Oh , Now that you know so much I might have to kill you... I'll let you know!

I sat down comfortably and got to work. Seconds later peace of mind went out the window! I hadnt noticed previously but the cylinder face and the end of the forcing cone are not parallel
I could get a 10thou blade in at the outer edge but I couldnt slide a 6thou blade down as far as the base pin.

Is this normal?
Do I need to do something about it?

I was also planning to point out that I have seen photos, on the web I believe, of a cylinder mod. Someone machined a groove for an o ring around the base pin hole with the intention of stopping anything from blowing into the base pin and its lube. I dont recall seeing any comment on how successful this was.

 

[Old Fuff]

I expect the Empire will crumble...

Take your feeler gauges in hand again, and place the hammer on half-cock so the cylinder can be revolved. Adjust the feelers so that when they are placed between the top strap and cylinder it can just turn. Turn the cylinder and see if any binding occurs. I doubt that it will, but if it does it means that the hole for the cylinder pin was drilled off center, and that would be bad.

If you get by this, the next (and most likely) thing is that the barrel was filed by a workman who didn't get it square. A skilled gunsmith could correct this by filing it square, and leave you with a consistent .010" gap, that would be acceptable.

But I wouldn't do anything unless the revolver's present accuracy isn't up to your expectations. If it was returned to Uberti (or whoever does their service work in the U.K.) I suspect they'd rebarrel it or replace the frame, whatever was called for.

 

[mukluk]

Just measured the barrel-cylinder gap on my Uberti Walker and 1860, both have a .002 gap. Can't tell you how many cylinders they'll go before they won't turn anymore... I've gone 8 cylinders on the Walker and 12 on the 1860 without relubing and they were still working like a charm.

 

[Old Fuff]

To a degree the gap can be adjusted by how far the wedge is driven in on a Colt style rvolver. Also with any of the popular cap & ball revolvers be sure to hold the cylinder fully backwards before measuring the gap. Otherwise the hand will push the cylinder forward, close the gap, and you'll get a wrong reading. Most black powder revolvers have substantial end shake, but this doesn't seem to bother them unless it is, or gets so bad that the caps won't fire reliably.

 

[Cincinnati Slim]

Cylinder-Barrel Gap

Howdy Folks,

It's a fact, black powder revolvers especially the cap and ball variety seem to run a lot better with a barrel-cylinder gap around .008-.010. A lot of the newer Italian guns are a bit too tight and the forcing cone end of the barrel is not really square. I got a Pietta 1860 and another 1851 and both had too tight of a gap and the top of the barrel was closer to the cylinder than the bottom. Not a big deal really but I like the R&D "drop-in" conversion cylinders and these usually are about .002-.003 than the percussion cylinders from the factory. I think R&D does this to tighten-up the usually large gaps typical of most percussion revolvers. A couple of minutes with a coarse followed by a fine Arkansaw knife sharpening stone will fix the problem. Of course the Colts are really easy to fix since the barrel is separate. Work slowly and take just a little off at a time, stopping often to test-fit. You only want to take off a couple thousands. They'll still be plenty of forcing cone area. Remingtons are a little tougher since you'll have to work inside the frame "window".

Mr."Mukluk", make sure your Walker is on half-cock and the cylinder is pushed back all the way against the hand/pawl spring. If the hammer is down and you try to measure the gap you'll be trying to shove the feeler gage in fighting the h*ll for strong mainspring pushing the cylinder forward against the barrel. 0.002 is mighty small, Are you getting you measurements on half cock ?

Cheers,

Slim

 

[DaveP (UK)]

The difficulty I face here is that my accuracy isnt up to my expectations

The cylinder isnt eccentric. Its axis might be not parallel to the bore but I doubt I have the resources to check that. Its probably not fixable anyway!
I think its just the end of the forcing cone, and I think I'll leave it be.
Assuming, as I am, that this isnt causing a problem using round balls, is it likely to be more of an issue if I try conicals one day?

 

[Old Fuff]

... is it likely to be more of an issue if I try conicals one day?

I doubt it so far as hand-held shooting is concerned. You might notice a slight difference if shooting from a rest. To get the maximum accuracy out of it would probably require setting the barrel back one turn and facing off the back end of it to make it square, Also, chamber vs. bore diameter could make a big difference. But now we're getting in to money for custom gunsmithing, and you might find the expence vs. accuracy improvements to be excessive..

 

[mukluk]

Half cock, cylinder pulled to rear:

 

[unspellable]

end shake vs wear & tear

With a cap and ball revolver the cylinder is blown to the rear on firing as seems intuitively obvious. The rear of the cylinder usualy has a large surface area abutting the frame, so wear or beating down is not much of a problem.

With a cartridge revolver, the situation is much less intuitive. The cylinder is blown FORWARD on firing. However, hand pressure, hammer impact, and primer protusion all tend to push the cylinder forward so that it is at the forward limit of travel when it fires. It's obvious that the crane tube bearing on the bottom of the cylinder well has a very small bearing surface so this is the weak point in the S&W. What's far less obvious is why excessive endplay accelerates the wear. I have not heard a good anwer for that.