Barrel / Cylinder alignment

[Vic]

Hi all!

I tried shooting it, and it does. Balls are accurate, bullets aren’t (quite expected though).

It’s an 1960-s Navy arms Uberti 1858 .36.

The question - is that step between barrel and cylinder acceptable? It’s my first revolver, so don’t know the limits of “acceptability” of such things.

As for me, looks scary )))

And as for remedy - I can only think of welding and remaking bolt cutouts on a cylinder?

 

[M. De Land]

Hi all!

I tried shooting it, and it does. Balls are accurate, bullets aren’t (quite expected though).

It’s an 1960-s Navy arms Uberti 1858 .36.

The question - is that step between barrel and cylinder acceptable? It’s my first revolver, so don’t know the limits of “acceptability” of such things.

As for me, looks scary )))

And as for remedy - I can only think of welding and remaking bolt cutouts on a cylinder?




View attachment 307675View attachment 307676View attachment 307677

Hi all!

I tried shooting it, and it does. Balls are accurate, bullets aren’t (quite expected though).

It’s an 1960-s Navy arms Uberti 1858 .36.

The question - is that step between barrel and cylinder acceptable? It’s my first revolver, so don’t know the limits of “acceptability” of such things.

As for me, looks scary )))

And as for remedy - I can only think of welding and remaking bolt cutouts on a cylinder?




View attachment 307675View attachment 307676View attachment 307677

Here is what I did to my early Pietta .44 target that both opened chamber mouths and aligned with the barrel bore making it much more accurate. It will out shoot my ROA !
I needed to open the chamber mouths to groove diameter and at the same time align them with the barrel bore. I pulled the barrel and made (lathe turned) a barrel spud that very closely fit the major thread diameter of the barrel hole into the frame and held the reamer I would use to a very tight slip bearing fit on the reamer shank. Run out was as close as I could make it and still get the spud into the barrel hole in the frame. I reamed each chamber mouth held in index by the guns own bolt, frame and knocks in the cylinder. This bored out and aligned the the chamber mouths with barrel bore at the same time. I call it line reaming ! The reamer holding barrel spud aligned the barrel hole through the frame to the cylinder notch index thus aligning the chamber mouths with the barrels bore.

 

[M. De Land]

Hi all!

I tried shooting it, and it does. Balls are accurate, bullets aren’t (quite expected though).

It’s an 1960-s Navy arms Uberti 1858 .36.

The question - is that step between barrel and cylinder acceptable? It’s my first revolver, so don’t know the limits of “acceptability” of such things.

As for me, looks scary )))

And as for remedy - I can only think of welding and remaking bolt cutouts on a cylinder?




View attachment 307675View attachment 307676View attachment 307677

Actually that is pretty common even in modern revolvers and I check it all the time with plug gauges. When it's really off they will spit lead. If it's only off a bit it can be corrected as described earlier but production revolvers are often this way.
Custom guns often have new cylinders made that are line bored and reamed in the frame they will be used in thus insuring perfect alignment.
It has always amazed me how accurately some production revolvers can shoot with virtually most of them having some degree of misalignment present.
If misalignment is more than the reaming of the chamber mouth will include (clean up with the larger diameter) than there is no fixing it by bore alignment reaming. In that case all that can be done is to open each chamber to groove diameter and live with the misalignment caused by bolt notch index.

 

[Bad Karma]

Here is what I did to my early Pietta .44 target that both opened chamber mouths and aligned with the barrel bore making it much more accurate. It will out shoot my ROA !
I needed to open the chamber mouths to groove diameter and at the same time align them with the barrel bore. I pulled the barrel and made (lathe turned) a barrel spud that very closely fit the major thread diameter of the barrel hole into the frame and held the reamer I would use to a very tight slip bearing fit on the reamer shank. Run out was as close as I could make it and still get the spud into the barrel hole in the frame. I reamed each chamber mouth held in index by the guns own bolt, frame and knocks in the cylinder. This bored out and aligned the the chamber mouths with barrel bore at the same time. I call it line reaming ! The reamer holding barrel spud aligned the barrel hole through the frame to the cylinder notch index thus aligning the chamber mouths with the barrels bore.

This is the way…

 

[M. De Land]

Hi all!

I tried shooting it, and it does. Balls are accurate, bullets aren’t (quite expected though).

It’s an 1960-s Navy arms Uberti 1858 .36.

The question - is that step between barrel and cylinder acceptable? It’s my first revolver, so don’t know the limits of “acceptability” of such things.

As for me, looks scary )))

And as for remedy - I can only think of welding and remaking bolt cutouts on a cylinder?




View attachment 307675View attachment 307676View attachment 307677

An other consideration of out of line chambers to the bore that effects bullet accuracy more than balls is that this misalignment is happening at bullet seating as well as when shooting. The rammer is stationary and each bullet being seated in each out of aligned chamber is being canted/tilted to the same degree thus presenting inconsistent bullet base square to the bore. The ball having a hemisphere base will hold accuracy better in misalignment than will a flat based bullet depending on level/square to bore seating for best accuracy.
Often when seating balls you will notice the cutting ring left will be an incomplete or out of round ring of lead. This is out of aligned chamber mouths in relation to the rammer holding the ball on it's center line when having a cupped/hemisphere seating face.
An incomplete lead cutting ring is an unsealed chamber subject to chain fire. This is another reason I have gone to over sized lubed felt wads under the balls or bullets.

 

[45D]

An other consideration of out of line chambers to the bore that effects bullet accuracy more than balls is that this misalignment is happening at bullet seating as well as when shooting. The rammer is stationary and each bullet being seated in each out of aligned chamber is being canted/tilted to the same degree thus presenting inconsistent bullet base square to the bore. The ball having a hemisphere base will hold accuracy better in misalignment than will a flat based bullet depending on level/square to bore seating for best accuracy.
Often when seating balls you will notice the cutting ring left will be an incomplete or out of round ring of lead. This is out of aligned chamber mouths in relation to the rammer holding the ball on it's center line when having a cupped/hemisphere seating face.
An incomplete lead cutting ring is an unsealed chamber subject to chain fire. This is another reason I have gone to over sized lubed felt wads under the balls or bullets.

Well, not really. Loading is normally
done with hammer on half cock which means the cylinder isn't locked in place like it is when firing. Of course, if you load with hammer at full cock or hammer down then you'd be correct possibly ( depending on the "why" it's out of alignment).

Mike

 

[M. De Land]

Well, not really. Loading is normally
done with hammer on half cock which means the cylinder isn't locked in place like it is when firing. Of course, if you load with hammer at full cock or hammer down then you'd be correct possibly ( depending on the "why" it's out of alignment).

Mike

That would be true if the chambers weren't off in the vertical axis as well as horizontal/radial axis which they often are ! That is why when reaming open frame gun chambers the center has to be located individually on both x-y axis with plug gauges instead of using frame and bolt index and a reaming spud as is done in solid frame revolvers.
Often when checking for misalignment I use a goose neck auto lamp as in the photos one can see exactly where the misalignment edge of the chamber mouth is positioned in relation to the bore one is looking through, it very often is in the 10-2-5 or 8 o'clock position indicating both axis misalignment.

 

[45D]

That would be true if the chambers weren't off in the vertical axis as well as horizontal/radial axis which they often are ! That is why when reaming open frame gun chambers the center has to be located individually on both x-y axis with plug gauges instead of using frame and bolt index and a reaming spud as is done in solid frame revolvers.
Often when checking for misalignment I use a goose neck auto lamp as in the photos one can see exactly where the misalignment edge of the chamber mouth is positioned in relation to the bore one is looking through, it very often is in the 10-2-5 or 8 o'clock position indicating both axis misalignment.

The OP's revolver is a '58 top strap frame. It looks to me that the chamber is past alignment. Top and bottom look OK. The fix ( if the locking notches are good) would be a new bolt and dressing only the "short side" if width adjustment is needed ( a bolt block may be a necessity). If a new bolt isn't available, moving material on the tall side to locate the surface further to the right may be the only solution. Hard to say really without seeing notches. A different cylinder may locate better . . . just need more info.

Mike

 

[M. De Land]

That would be true if the chambers weren't off in the vertical axis as well as horizontal/radial axis which they often are ! That is why when reaming open frame gun chambers the center has to be located individually on both x-y axis with plug gauges instead of using frame and bolt index and a reaming spud as is done in solid frame revolvers.
Often when checking for misalignment I use a goose neck auto lamp as in the photos one can see exactly where the misalignment edge of the chamber mouth is positioned in relation to the bore one is looking through, it very often is in the 10-2-5 or 8 o'clock position indicating both axis misalignment.

When looking down a bore with a small goose neck auto lamp one can index each chamber to lock up position then line up the bore with the chamber mouth around the perimeter and can gauge with in a .001 or two of misalignment amount and position. The reason is the same as why double aperture globe sights are so accurate because one is viewing a circle through a circle.
To check vertical misalignment all one has to do is go to half cock and manually turn the the chamber to top center and note how the bore lines up with chamber mouth at 12 and 6 o'clock in the vertical plane. It is quite common for them to be off in both axis, to one degree or another.
I've not tried fixing horizontal misalignment by making a new wider off set bolt but it's theoretically possible using the same cylinder notches, the trouble is the window also will need modification.

 

[Vic]

The OP's revolver is a '58 top strap frame. It looks to me that the chamber is past alignment. Top and bottom look OK. The fix ( if the locking notches are good) would be a new bolt and dressing only the "short side" if width adjustment is needed ( a bolt block may be a necessity). If a new bolt isn't available, moving material on the tall side to locate the surface further to the right may be the only solution. Hard to say really without seeing notches. A different cylinder may locate better . . . just need more info.

Mike

Thanks everyone for answers!

Yes, the chamber travels a little past the barrel, and then locks. The bolt has already been “tuned” back in the days ))

Anyway, I got an answer - it’s a common thing )))

 

[Vic]

Here is what I did to my early Pietta .44 target that both opened chamber mouths and aligned with the barrel bore making it much more accurate. It will out shoot my ROA !
I needed to open the chamber mouths to groove diameter and at the same time align them with the barrel bore. I pulled the barrel and made (lathe turned) a barrel spud that very closely fit the major thread diameter of the barrel hole into the frame and held the reamer I would use to a very tight slip bearing fit on the reamer shank. Run out was as close as I could make it and still get the spud into the barrel hole in the frame. I reamed each chamber mouth held in index by the guns own bolt, frame and knocks in the cylinder. This bored out and aligned the the chamber mouths with barrel bore at the same time. I call it line reaming ! The reamer holding barrel spud aligned the barrel hole through the frame to the cylinder notch index thus aligning the chamber mouths with the barrels bore.

Thanks a lot! I gotta use some tech dictionary to fully understand everything ))) Glad that Pietta target finally became a good shooter ))

This one seemed quite ok for a range fun with balls and 17 grns - all in black, target 7 steps away. First time shooting pistol. I will gather more group/load info, and, more than sure, will not do anything to it )))

 

[45D]

Last pic shows "tall" side of bolt. It also shows some space that should be plenty to allow bolt to locate in a correct position. You should be able to rotate cylinder backwards with hammer down and have the chamber line up with the bore. If not, bolt width may need to be adjusted.
If you can't do that with the hammer at full cock, that means the hand is a little long.

Funny how the SA revolver is often described as "simple" ( and "number of parts" wise, it is), but there is a LOT of "technicality" involved if one is to run "correctly".

Mike

 

[M. De Land]

Thanks everyone for answers!

Yes, the chamber travels a little past the barrel, and then locks. The bolt has already been “tuned” back in the days ))

Anyway, I got an answer - it’s a common thing )))


View attachment 308340

View attachment 308341

View attachment 308342

Note the nick on the back side of the bolt notch in the cylinder. That is either a cam wear problem, to long of a hand nose fit or the bolt nose is to high . The bolt nose is catching the top of the notch before it clears.
As there is no drag line on the cylinder I think Mike made the correct call on to long a hand nose starting the turn before the cam has lifted the bolt high enough to clear the back edge.

 

[M. De Land]

Thanks a lot! I gotta use some tech dictionary to fully understand everything ))) Glad that Pietta target finally became a good shooter ))

This one seemed quite ok for a range fun with balls and 17 grns - all in black, target 7 steps away. First time shooting pistol. I will gather more group/load info, and, more than sure, will not do anything to it )))

Typically revolvers are checked for alignment with a tool called a range rod that is poked down bore and into each chamber to see if the rod will go clear to the bottom. If it won't than there is misalignment.
I do this with precision plug gauges two inches in length as large in diameter as will slide down the bore. I put the largest one that will slide down bore in the muzzle and tip the muzzle up to see if they will drop to the bottom of each chamber of their own weight.
I measure the depth of each with a cleaning rod to check because some chambers are to misaligned to allow full passage of the plug gauge.
When the plugs will drop to the bottom of each chamber of their own accord one has a revolver with very good alignment.

 

[borne2fly]

An other consideration of out of line chambers to the bore that effects bullet accuracy more than balls is that this misalignment is happening at bullet seating as well as when shooting. The rammer is stationary and each bullet being seated in each out of aligned chamber is being canted/tilted to the same degree thus presenting inconsistent bullet base square to the bore. The ball having a hemisphere base will hold accuracy better in misalignment than will a flat based bullet depending on level/square to bore seating for best accuracy.
Often when seating balls you will notice the cutting ring left will be an incomplete or out of round ring of lead. This is out of aligned chamber mouths in relation to the rammer holding the ball on it's center line when having a cupped/hemisphere seating face.
An incomplete lead cutting ring is an unsealed chamber subject to chain fire. This is another reason I have gone to over sized lubed felt wads under the balls or bullets.

Is there a way to correct this misalignment, assuming it's present even with the cylinder locked into position by the bolt?
Also, I suppose it could happen in either direction (over or under rotated), so I'm wondering how each case would be addressed.

 

[borne2fly]

Is there a way to correct this misalignment, assuming it's present even with the cylinder locked into position by the bolt?
Also, I suppose it could happen in either direction (over or under rotated), so I'm wondering how each case would be addressed.

I'm guessing the fix would be to shift the bolt left or right. But if it's so bad that this isn't enough .... re-machine the notches?

 

[M. De Land]

I'm guessing the fix would be to shift the bolt left or right. But if it's so bad that this isn't enough .... re-machine the notches?

 

[M. De Land]

I don't know of any fix for vertical misalignment except reaming over size to groove diameter or fitting a new cylinder but for horizontal misalignment I would make a new bolt with a wider body and off set head to which ever side was needed. This would necessitate the window to be widened as well to accommodate the wider bolt body that would be offset one way or the other to facilitate alignment. The bolt width must both fit the cylinder notch (bolt nose/top) and window well (lower bolt body) to maintain alignment which is how the wider off set bolt and window would allow this. The increased bolt width is how we get the offset and still maintain cylinder notch width fit.
The cylinder notches are indexed/timed to the ratchet star and hand length so could not be moved.

 

[borne2fly]

I don't know of any fix for vertical misalignment except reaming over size to groove diameter or fitting a new cylinder but for horizontal misalignment I would make a new bolt with a wider body and off set head to which ever side was needed. This would necessitate the window to be widened as well to accommodate the wider bolt body that would be offset one way or the other to facilitate alignment. The bolt width must both fit the cylinder notch (bolt nose/top) and window well (lower bolt body) to maintain alignment which is how the wider off set bolt and window would allow this. The increased bolt width is how we get the offset and still maintain cylinder notch width fit.
The cylinder notches are indexed/timed to the ratchet star and hand length so could not be moved.

I don't know of any fix for vertical misalignment except reaming over size to groove diameter or fitting a new cylinder but for horizontal misalignment I would make a new bolt with a wider body and off set head to which ever side was needed. This would necessitate the window to be widened as well to accommodate the wider bolt body that would be offset one way or the other to facilitate alignment. The bolt width must both fit the cylinder notch (bolt nose/top) and window well (lower bolt body) to maintain alignment which is how the wider off set bolt and window would allow this. The increased bolt width is how we get the offset and still maintain cylinder notch width fit.
The cylinder notches are indexed/timed to the ratchet star and hand length so could not be moved.

Ahh, good! I was hoping it would be something like that … pretty straightforward machine work. Thanks!

 

[M. De Land]

Ahh, good! I was hoping it would be something like that … pretty straightforward machine work. Thanks!

I've hand machined quite a few internal gun parts but a new bolt from bar stock would be a real job,especially the fingers, to get right. What I would do is either TIG weld the bolt head wider and mill to fit the enlarged window width then mill the off set on the top end to fit the cylinder notches or more likely silver solder on a laminate of spring stock and mill down to fit the offset notch width.
The spring stock laminate would probably be the way to go and low temp silver solder/sweating it to the upper bolt nose after heat treating. A carbide mill would do the width trim and offset with final fitting via a diamond file.
I like and use a lot of Force 44 low temp silver solder for work like this as it has 2/3rds the shear strength of high temp silver solder and would be more than adequate to the job.