Cylinder Gap

[Billy Bristol]

well in the 40 yrs I have been doing gunsmithing  on C&B revolvers the gap has always been measured by pulling the the cylinder back. Also my barrel is not recessed below the frame. And all the ones I have ever worked on that were not converted did not have the barrel recessed from the frame. therefore there was no gap when cylinder was pushed forward. Once the firearm was fired the cylinder would be pushed back from the pressure thus creating the gap.

I noticed in the photo below that the remmie was converted. Not being familiar with the conversions, it mat be different and thus fitted like a newer cartridge firearm. meaning the barrel may be reworked to be recessed t create the gap. I will have to look into this further. As I said I am not familiar with conversions.

[carbineone]

OK, here is what I have and think is going on in my particuliar situation. When I hold the cylinder forward tight and the front of the cylinder is tight against the boss where the pin goes through I have a .06 gap between the barrel and cylinder. At the same time when it is held forward I have a large gap at the rear of the cylinder between the frame and back of cylinder (.025).

Obviously from what you guys have told me, my barrel to cylinder gap is fine and my problem is just too much wear at the rear, causing the barrel gap to open way to wide when the recoil sends the cylinder rearward against the frame, hence opening the very large gap between the front.

Probably mostly the frame is wore and my serial numbers on the cylinder do not appear to have a lot of wear. I am sure it is a combination of both cylinder and frame wear though. The frame is either stretched or just wore from the cylinder hammering and turning back there.

As I said I think my front is fine with the the .006 gap at the barrel but I need to shim the rear to lessen the gap between the rear of the cylinder and the frame at the rear.

When I put the shim in the rear I made. The front gap is good and the revolver functions just fine and the horizontal back and forth play disaapears.    

I have home gunsmithed and have worked on ALOT of firearms in the last 30 years. Antique and modern and it appears my problem can be fixed by curing the slop from the rear. Maybe I am wrong, but that seems to be what I need to do...Thanks

[Billy Bristol]

Carbine,

Without having the firearm in my hands, and as you described, that sounds like it would work. But I would suggest after shimming the rear to make sure you have proper chamber to barrel alignment. Since the cylinder is now forward the pawl may or may not rotate the cylinder as far. With the cylinder farther forward it can change timing a bit. It may be so small a change that it will not interfere enough to bother with but is worth checking.

[carbineone]

Billy, with the shim in there the timing still works great. The cylinder bolt locks the cylinder just as it should and the hand still operates just fine... And the barrel aligns perfectly..

I may decide to decide to pull my barrel and stick it in my lathe and get the barrel turned in another turn and go from there. That would probably be the correct way to do it..I will think on it.. i know that would open up the cylinder pin gap but I could deal with that too. May have to work on the forcing cone a little too..

Thanks

[Billy Bristol]

Carbine,

Just went through all the posts here. Did not notice something. Is your remmie an italian clone or an original?

If it is a clone, there are 2 different cylinder lengths in these. One is 2.000 and the other is 2.015. If the shorter cylinder is put into the wrong firearm it will create a back and forth shake but may still lock up properly.

[carbineone]

It is an original. That is why I may be a little hesitant to mess with it, but if it does not work properly it will have to be disposed of

[carbineone]

Well we have a snowstorm going on today so I went ahead and did it. I soaked the barrel threads with PB Blaster (great stuff by the way) I then clamped  the barrel in a padded vice. Then all I had to do was grab the frame with both hands and twist the frame off the barrel. Did not have to use any kind of tools to remove it, which made me very happy..

I then chucked the barrel in my lathe and had to eventually remove around .030 to get a good tight fit again and barrel alignment. You cannot tell I did it and never left any tool marks or any evidence the barrel was ever removed and altered.  It appears they use a 28 thread pitch on their barrels so in actuality, I should have had to remove about one full thread which would be .035 but all worked well..

The cylinder now locks up very nice and tight in the cylinder bolt stops. The whole Firearm is tighter and even the sound when turning the cylinder sound more like it should. Just sounded loose before when turning it. Sounded more like a cheap loose gun when cocking it and turning the cylinder if you know what I am saying. Sounds like a quality built Remington now now..

Most importantly the barrel gap is right again. No more .030 gap there to blow out crap.

Anyway very happy and will try to shoot it once after the Snowstorm clears and let you all know how it went. Thanks to everybody. I appreciate all the input...Bruce

[carbineone]

Well pretty decent today after the big storm so I loaded the old girl up and took it out and shot it.

I am very, very, happy how it performed. Shot accurrate, rotated smoothly through all six shots, and functioned very smooth. Pin was very clean when I removed it.. Thanks.

[Billy Bristol]

Glad to hear it worked out for ya.

[Fairshake]

In my 5 Smith & Wesson Armour's schools that I attended in Springfield, Mass. and was taught by John Contro . We were always taught to measure cylinder gap by pulling the cylinder to the rear not forward as posted by DJ.
When a revolver is fired the cylinder is forced to the rear against the recoil shield. It is at this time that having too much or too little barrel cylinder gap will give you problems.
The factory teaches you how to lengthen the cylinder pin to cure too much and how to shorten it to have more. Today many people just use the copper shims that are sold in different sizes.
This problem is called endshake when it is too big.
When Jim Finch set up my two pair of USFA revolvers for shooting BP in SASS so that they would run the entire match, he set them up at .007
I also use a liberal amount of Mobil 1 grease on the cylinder pin and the bushing. My guns are turning the same at the end as they did at the start. Later David

[carbineone]

Right at .008 is what I have now when the cylinder is pushed firmly to the rear. Any thought on what the clearance should be at the base pin at the front of the cylinder? Maybe the same .007? Thanks

[Billy Bristol]

Carbine,

I have always had mine set between .005 and .008. I have never had a problem shooting mine. I usually load mine with powder, ball and crisco over ball. I have put as many as 60 shots through mine with no problems or cleaning, other than wiping down outside. I know many of guys put a wad under the ball instead of lube over the ball. I haven't tried that even though it makes more sense for keeping the barrel cleaner since the wad follows the ball down the barrel.

[rifle]

I'd say....the barrel being set back to create a .008 cylinder/barrel gap I'd wonder if the cylinder/barrel boss gap has been set to keep the gap at the barrel close to .008. or does the cylinder now rub the barrel when the gun action is worked. You know what I mean? The boss not keeping the cylinder off the barrel? The barrel acting as the boss should?
There may be a need to make a bushing to add to the space between the cylinder and the frame boss to keep the cylinder off the barrel as it should be. 
The shim at the cylinder/boss junction should keep the cylinder gap at .006 (when the gun is at rest)with a gap at the boss or behind the cylinder of about .002 so the final gap is the .008 you set the barrel at.
Sound right?
If the frame at the rear of the cylinder has any deformation from years of cylinder bang to it then it'll need a lil space there like the .002 mentioned. Fouling finds it's way into the cylinder center hole and onto the base pin at the rear also so the less gap there the better......close but not dragging from a lil fouling building
If you set the barrel back to where the frame boss is useless then the gun will have the trait of the cylinder being able to drag on the barrel like a Colt. That'll work but the boss doing it's job is how it should be right?

[carbineone]

Your oberservations are right on and I did not mention it earlier but here is how I overcame that. I did not want to particuliar do such a modification, but to me if this thing is not tight and shootable I have no use for it.

I am not one to just collect and use firearms as a poster on the wall. If it is unshootable I just as well  have  pictures I hang on the wall of Firearms. And this is not a High Condition Revolver to begin with and is was bought as a shooting project.

I put the cylinder in the Bridgeport mill and milled a shallow 5/16 inch inset shoulder and put a 5/16 inch bronze bushing in the end using red loctite to make sure it stays in place. Then reamed the bushing to size after loctiting it in.  A little bonus to doing this, is there is now a little protrusion there that should help deflect some of the crap away from the pin too...

I may replace the bronze bushing with a steel one eventually, but if the bronze holds up OK I will let it there..

Anyway gotta do what you have to sometimes..Thanks

[rifle]

Well, that bronze bushing is better than using a shim as I had mentioned. That is a better way.....the bronze bushing.
How do you set up to rebate the center clyinder hole for the bushing. Reaming it with a piloted reamer means a little off center with the outside of the bushing doesn't matter if the inside is lined up with the center cylinder hole. You use piloted reamer fer that?
I like piloted reamers especially if the pilot is snug enough.
Anywhoooo......wish I had a lathe.
Is  the frame of that gun beat in or banged up from the cylinder slamming back with recoil? I've seen where the cylinders sometimes make a round dented in area where the cylinder has hit many times. Not always all the same deapth from the cylinder being loose on the cylinder pin. You know.....the top,usually, deeper than the bottom of the dented in area.
Thanks fer showin the pic of the bronze bushing. It'll turn blackish from fouling stain and look like dark steel after awhile right?

[carbineone]

No the back is not beat real bad at all..

How I did the bushing is I used a Bridgeport Mill with a 5/16 endmill in it. I put a 1/4 inch bit it the bridgeport. Used the drill bit to center the cylinder in the vise and clamped the cylinder down with a piece of wood on each side to protect it.. Removed the drill bit and put in the endmill and went in the depth I wanted. Then I simply used a drill bit to do the inside finish reaming..

Worked very well.   I actually do not have a Bridgeport or a Lathe myself. I sometimes call it mine as I use it all the time whenever I want to. It belongs to a friend..He gives me unlimited access to it anytime I need it..

[rifle]

I've used "feelers" like drill bits or drill rod to center in existing holes. There are methods for centering on a round stock to drill center but never found a true method for centering on an existing hole. That's why I'd make a feeler,as I call them, the closest to the diameter ofthe hole and leave the end sharppedged so if it wasn't lined up to the hole realclose it wouldn't go in. I got tired of making the drill rod the exact size I needed to fit the holes closely. I had a collection of them after awhile.
I had Starrett make me a centering tool to put in the mill made from a center finder/edge finder. The method was to use a center finder/edge finder with a larger cone shaped end on one side that was a half inch. In a round hole it (the cone shaped end)can be brought down in the mills drill chuck into the hole of the work piece in the mill machine vise and then lined up using the x and y axis by fiddling around for awhile.
The center can be found with a small tolerance and in things like percussion revolver cylinder chambers the center finder tool can be removed and replaced by a chucking reamer of the appropriate size for reaming the chambers to the right size for the grooves of the barrel. Makes the revolvers shoot better/more accurate.
Before that I had gone to a piloted reamer with changeble pilots so I could use the same reamer for different size chambers. The tool with the pilots cost money and the pilots cost a pretty penny too since the tolerance was less than a .001 inch.
Some people use adjustab;e reamers to ream chambers but the ends limit how deep you can ream.
Anywhoooo...... this all means that using a "feeler" like you did to center on the hole is about the simplest way to get it done.....and.....
since you reamed the center hole using the existing cylinder center hole as a pilot you get a good job in the end where it matters most.....at the center hole.
If you ever ream chambers to be at the same diameter as the barrels grooves using a "feeler" can work good enough if it's real close to the size of the hole it's going into.
Anywhoooo....I know of a method for making a cylinder bushing like you did for the Remington for a Colt. On a Colt the bushing isn't as good as on a Remington because it needs split because of the underside of the Colts barrel under the forcing cone. The split can be eliminated though by milling a little off the underside of the barrel and working that end of the bushing down at an angle. Sorta like the Open Top 1871 is done.

[carbineone]

Thanks good info. I am far from a Proffesional Machinist. I just like doing this stuff and have worked on all kinds of Firearms as a Hobby since I was a kid.

I do have a proffesional Machinist friend also if I ever need to do something I do not think I can handle. I have not ran across that scenario yet however. Mostly I just take my time and think things through and use what common sense I have

[rifle]

Sound Wisdom Hombre. Sound Wisdom.