restoring a cam on an 1860 hammer

[M. De Land]

I'm waiting for the third lap to cool in the barrel and should be finished up before to long.
I forgot to tell the groove diameter which is .444 in this barrel. The chamber mouths are . 446 so except for a little radial lap to clean up the mouths we should be in pretty good shape.
I did note that the grooves are a bit deeper on one side of the bore than the other and these barrels looked buttoned to me which seems odd but I suppose a button can be ground out of spec just as a broach can. I used to have a Taurus revolver that had this very noticeable defect but seemed pretty accurate anyway. It bugged me so I finally sold the gun.
The laps are pure lead because it shrinks more than does lead alloy which is needed for lap compound clearance to keep it from sticking in the bore.
I started with 400 grit to get the lap moving then added 220 once it was freed up. I sure could feel the tight spot the plug gauges found near the breech.
I like to re-cast a new lap every 250 round trips (five hundred passes) in the bore and recharge the lap every 50 cycles.
Lapping is mostly done by feel and the trick is to work out the tight spots and blend them with the more open until you get the bore even or with a bit of choke toward the muzzle which is what I usually try to do.
I finish up with 400 grit which works out well.

Lap slugs are interesting to examine once they are impregnated with lap compound and are working as they reveal more of the bore and groove profiles high and low spots. A well executed lap job will never hurt a bore but done carelessly can absolutely ruin one.
It will often make little change in a well drilled, reamed and rifled barrel but can make a real hummer out of one that is fairly ragged in finish or rough from poor cleaning and neglect.
It cuts off all the burrs on land corners left from machining and smooths groove bottoms. The lands being the highest points in a bore get the lions share of reduction though and the grooves much less so.
I did one rifle barrel that required 7 lap casts , three grit changes and 2500 cycles to get it even. Thought my arms were going fall off but they didn't.
Pistol barrels being much shorter require far less work than does a full length rifle barrel but have there own unique challenge hurdles.
I have found that leading almost never is caused by pitting but rather tight spots that open up and then let gas pressure by the base. Patched balls seem much less effected by this than lead conicals but I some times wonder if it is not one of the reasons for burned holes in patch material.

 

[M. De Land]

Funny you say that, I do it several times a week ( unless I have some Remingtons or ROA's).



That's about right, I set them at .0025" - .003" for cap guns, .0015" - .002" for unmentionables using smokeless.

Endshake pretty much determines the "life" of the revolver. . . . especially "high power" target S.A.'s.

Mike

Yeah, on the solid frame guns it's lots of work setting back a barrel thread and shortening/ refitting the loading lever .

 

[45D]

Yeah, on the solid frame guns it's lots of work setting back a barrel thread and shortening/ refitting the loading lever .

Yes it is !! I don't do that. I've heard too many horror stories about Pietta Remingtons tearing out threads and such so, never gave it a thought! Lol.

Mike

 

[M. De Land]

Yes it is !! I don't do that. I've heard too many horror stories about Pietta Remingtons tearing out threads and such so, never gave it a thought! Lol.

Mike

My Pietta 58 barrel came out normally. I pulled the barrel , incerted a reamer guide in the frame and line reamed the chamber mouths.

 

[45D]

Some say they were assembled with crazy thread-locker and blah blah blah. I'm not into buying barrels and frames . . . I spend enough time just doing what I do on the inside!!

Mike

 

[M. De Land]

Lap slugs are interesting to examine once they are impregnated with lap compound and are working as they reveal more of the bore and groove profiles high and low spots. A well executed lap job will never hurt a bore but done carelessly can absolutely ruin one.
It will often make little change in a well drilled, reamed and rifled barrel but can make a real hummer out of one that is fairly ragged in finish or rough from poor cleaning and neglect.
It cuts off all the burrs on land corners left from machining and smooths groove bottoms. The lands being the highest points in a bore get the lions share of reduction though and the grooves much less so.
I did one rifle barrel that required 7 lap casts , three grit changes and 2500 cycles to get it even. Thought my arms were going fall off but they didn't.
Pistol barrels being much shorter require far less work than does a full length rifle barrel but have there own unique challenge hurdles.
I have found that leading almost never is caused by pitting but rather tight spots that open up and then let gas pressure by the base. Patched balls seem much less effected by this than lead conicals but I some times wonder if it is not one of the reasons for burned holes in patch material.

I decided to go ahead and ream the chamber mouths so will show that when the reamer gets here. Mean while I have a Remington Roller to re-barrel and a Stevens 44 rebuild to stock.
Always something to fix around here ! I should start a U-tube channel and sell T shirts !

 

[45D]

I forgot to mention that I did end fit the arbor with a disk shim and it was quite a simple operation. This arbor well had a perfectly flat bottom which I have not seen before. That I still had to use a shim disk to reach the well bottom was quite amazing considering the . 020 plus set back I had to take out to tighten up the barrel/cylinder gap.

Since you added a shim in the arbor hole after you had removed material at the frame / barrel butt joint ( for correction purposes), what did that do for that joint? I would think you have much less "applied" tension on that joint and possibly a slight "space" there? In my experience (as well as another well known tuner/smith) it's quite rare for the need to remove material at that joint and maintain sufficient tension at that joint with the wedge driven in.

Mike

 

[M. De Land]

Since you added a shim in the arbor hole after you had removed material at the frame / barrel butt joint ( for correction purposes), what did that do for that joint? I would think you have much less "applied" tension on that joint and possibly a slight "space" there? In my experience (as well as another well known tuner/smith) it's quite rare for the need to remove material at that joint and maintain sufficient tension at that joint with the wedge driven in.

Mike

It still required a .009 shim disk to make contact with the arbor well bottom and keep the barrel/cylinder gap as even as I could make it. I started with a .012 shim disk that was showing contact (compression shine in the middle of disk) and kept adjusting down (progressively thinner shim stock) until the barrel gap evened up with the wedge driven in with a few hits from a rawhide mallet. It's still not perfect but as close as I could get it without a lot of extra work. Actually I would prefer it a bit tighter at the top of the gap as I know under load at firing the metal compression will even the gap out more.
At maximum feeler gauge check before barrel reduction began the gap was somewhere in the area of .027. I set it back .023-024 and still the arbor was not bottoming out in the well.
The challenge of the lug reduction was to not get ahead of the wedge pull and end fit because of the angular cantilever effect.
I believe that very close lug to frame fit with tight pins is one of the primary accuracy "force multipliers" ,in open frame guns.

 

[M. De Land]

Since you added a shim in the arbor hole after you had removed material at the frame / barrel butt joint ( for correction purposes), what did that do for that joint? I would think you have much less "applied" tension on that joint and possibly a slight "space" there? In my experience (as well as another well known tuner/smith) it's quite rare for the need to remove material at that joint and maintain sufficient tension at that joint with the wedge driven in.

Mike

Ideally the wedge draw of the arbor in the well will be in parallel co-axis with the bore and the lug should support it with firm and direct cantilever support to maintain bore co-axis with the chambers. The lug contact needs to be solid with no gaps to the frame. The pins need to be tightly fit to their hole seats to eliminate radial movement from bullet torque. This is hard to accomplish with so many slip fit tolerances needed to make this system work by hand assembly.
All these tolerances have movement in them at firing so the challenge is to get these to all move the same minimal amount each time sinse there is no posiblily of avoiding it all. 1911 pistols for example are tuned with the same thinking , each movement is held to as close a fit as possible and still maintain reliability. Each upgrade to movement adds a percentage to accuracy potential so that when totaled it makes the whole machine function more efficiently .reliably and accurately.

 

[M. De Land]

Ideally the wedge draw of the arbor in the well will be in parallel co-axis with the bore and the lug should support it with firm and direct cantilever support to maintain bore co-axis with the chambers. The lug contact needs to be solid with no gaps to the frame. The pins need to be tightly fit to their hole seats to eliminate radial movement from bullet torque. This is hard to accomplish with so many slip fit tolerances needed to make this system work by hand assembly.
All these tolerances have movement in them at firing so the challenge is to get these to all move the same minimal amount each time sinse there is no posiblily of avoiding it all. 1911 pistols for example are tuned with the same thinking , each movement is held to as close a fit as possible and still maintain reliability. Each upgrade to movement adds a percentage to accuracy potential so that when totaled it makes the whole machine function more efficiently .reliably and accurately.

I've been chewing on how best to do this ream job with the least chance of causing a chatter to get going and I think I have a better solution than doing it in the mill with a cross axis feed mill table. I think what I'm going to do is set it up in my lathe with the cylinder in the mill attachment secured by two opposing V blocks (if the jaws are wide enough) and the reamer in the head stock. I'll use a plug gauge to find center on each chamber, back off and change to the reamer then set depth with the micrometer table stop on the lathe ways. I can turn the reamer by hand from the drive pulley or as I do in barrel chamber reaming use the back gear at a very slow RPM.
This should give me maximum control over any chance of a chatter getting started with a pilot-less reamer. Once a chatter gets started in any kind of precision chamber work they are pure hell to get rid of!
I learned while making reamers how that off setting each flute a degree or two ahead or behind the preceeding one is a factor in reamer design to discourage harmonic induced chatter but don't know if these chucking reamers are set up this way hence the need to go slow with them.
If this works as intended I'll have a better method for reaming cylinder chambers for new cartridges as well.

 

[Bad Karma]

I've been chewing on how best to do this ream job with the least chance of causing a chatter to get going and I think I have a better solution than doing it in the mill with a cross axis feed mill table. I think what I'm going to do is set it up in my lathe with the cylinder in the mill attachment secured by two opposing V blocks (if the jaws are wide enough) and the reamer in the head stock. I'll use a plug gauge to find center on each chamber, back off and change to the reamer then set depth with the micrometer table stop on the lathe ways. I can turn the reamer by hand from the drive pulley or as I do in barrel chamber reaming use the back gear at a very slow RPM.
This should give me maximum control over any chance of a chatter getting started with a pilot-less reamer. Once a chatter gets started in any kind of precision chamber work they are pure hell to get rid of!
I learned while making reamers how that off setting each flute a degree or two ahead or behind the preceeding one is a factor in reamer design to discourage harmonic induced chatter but don't know if these chucking reamers are set up this way hence the need to go slow with them.
If this works as intended I'll have a better method for reaming cylinder chambers for new cartridges as well.

I’ve done the same thing on my drill press and then used a 5” long spanner to turn the reamer into the chambers. Worked very well.

 

[M. De Land]

I’ve done the same thing on my drill press and then used a 5” long spanner to turn the reamer into the chambers. Worked very well.

You were way ahead of me on this. I did one in the drill press and one other with a reamer guide through the frame by hand which I think is the absolute best method but not available to open frame cylinders. I got a chatter going with my drill press and should have turned it by hand instead of turning on the motor. It was centered too but it still chattered. Never would have happened had I turned the drive pulley by hand.
Some times it's " to soon old , to late smart" !

 

[Bad Karma]

You were way ahead of me on this. I did one in the drill press and one other with a reamer guide through the frame by hand which I think is the absolute best method but not available to open frame cylinders. I got a chatter going with my drill press and should have turned it by hand instead of turning on the motor. It was centered too but it still chattered. Never would have happened had I turned the drive pulley by hand.
Some times it's " to soon old , to late smart" !

One thing I have learned is just how quickly I can turn parts into scrap metal with power tools…

 

[M. De Land]

I've been chewing on how best to do this ream job with the least chance of causing a chatter to get going and I think I have a better solution than doing it in the mill with a cross axis feed mill table. I think what I'm going to do is set it up in my lathe with the cylinder in the mill attachment secured by two opposing V blocks (if the jaws are wide enough) and the reamer in the head stock. I'll use a plug gauge to find center on each chamber, back off and change to the reamer then set depth with the micrometer table stop on the lathe ways. I can turn the reamer by hand from the drive pulley or as I do in barrel chamber reaming use the back gear at a very slow RPM.
This should give me maximum control over any chance of a chatter getting started with a pilot-less reamer. Once a chatter gets started in any kind of precision chamber work they are pure hell to get rid of!
I learned while making reamers how that off setting each flute a degree or two ahead or behind the preceeding one is a factor in reamer design to discourage harmonic induced chatter but don't know if these chucking reamers are set up this way hence the need to go slow with them.
If this works as intended I'll have a better method for reaming cylinder chambers for new cartridges as well.

The .448 chucking reamer showed up on my porch from MSC so will be reaming all the chamber mouths , I think I'll do this in my lathe with the milling table if all goes as planned it should be the easiest set up. It gives me the x-y axis adjustment needed to get dead nuts center with the reamer in the three jaw chuck. I have a head stock collet but the three jaw will be plenty accurate for plug gauge to find center and then reamer purchase to cut the chamber mouths all the same by hand turning the belt pully of the head stock. A lot less chance of getting a chatter going.

 

[M. De Land]

The .448 chucking reamer showed up on my porch from MSC so will be reaming all the chamber mouths , I think I'll do this in my lathe with the milling table if all goes as planned it should be the easiest set up. It gives me the x-y axis adjustment needed to get dead nuts center with the reamer in the three jaw chuck. I have a head stock collet but the three jaw will be plenty accurate for plug gauge to find center and then reamer purchase to cut the chamber mouths all the same by hand turning the belt pully of the head stock. A lot less chance of getting a chatter going.

Here is the set up I'm going to use as my lathe mill table will not except the width of the V Blocks. The x-y cross axis feed on the milling table is how we make precise reamer center placement keeping it square to chambers.The plug gauge is used to find center of each chamber , removed and replaced with the reamer. A steel plug is dropped into each chamber for the reamer to butt against for precise depth control. I have removed the pulley safety head and will turn by hand to lesson the chance of reamer chatter while cutting with this method.
Each chamber has to be re-centered with a plug gauge before reaming. Slow but about as precise as can be accomplished without in frame line boring which is not an easy option with open frame guns.
Oh, I forgot to mention this set up is in my radial arm drill press.

 

[M. De Land]

Here is the set up I'm going to use as my lathe mill table will not except the width of the V Blocks. The x-y cross axis feed on the milling table is how we make precise reamer center placement keeping it square to chambers.The plug gauge is used to find center of each chamber , removed and replaced with the reamer. A steel plug is dropped into each chamber for the reamer to butt against for precise depth control. I have removed the pulley safety head and will turn by hand to lesson the chance of reamer chatter while cutting with this method.
Each chamber has to be re-centered with a plug gauge before reaming. Slow but about as precise as can be accomplished without in frame line boring which is not an easy option with open frame guns.
Oh, I forgot to mention this set up is in my radial arm drill press.

Well the chambers are reamed and honed to the existing hole placement. I was satisfied with the reamer center as I was taking material from the whole chamber and when only removing a couple of thousandths out of center shows up immediately. No chatter and was able to use the power after doing the first one by hand.
Put her all back together and she locks up tighter than Dicks hatband which was gratifying but had to give her one more check and that was the range rod check. I dropped the biggest plug gauge down barrel that the bore was lapped to and three of the chambers excepted the gauge by gravity................. the other three would not and the plug gauge stopped at the chamber mouth. It looks like the three that would not except the gauge are out of alignment on the vertical by a couple thousands as I could not get the gauge to drop moving the chamber forward and backward a bit.
I'll go and give her a range test and see what kind of accuracy I can get over sand bags.
My Pietta by comparison excepted the tightest plug gauge that would drop through the lapped bore into all chambers so it's alignment is excellent.
The picture in the middle is the plug depth gauge used to make all the chamber mouths the same.
In the chamber ream picture four holes are reamed and two were not done yet to show the difference.

 

[Bad Karma]

Well the chambers are reamed and honed to the existing hole placement. I was satisfied with the reamer center as I was taking material from the whole chamber and when only removing a couple of thousandths out of center shows up immediately. No chatter and was able to use the power after doing the first one by hand.
Put her all back together and she locks up tighter than Dicks hatband which was gratifying but had to give her one more check and that was the range rod check. I dropped the biggest plug gauge down barrel that the bore was lapped to and three of the chambers excepted the gauge by gravity................. the other three would not and the plug gauge stopped at the chamber mouth. It looks like the three that would not except the gauge are out of alignment on the vertical by a couple thousands as I could not get the gauge to drop moving the chamber forward and backward a bit.
I'll go and give her a range test and see what kind of accuracy I can get over sand bags.
My Pietta by comparison excepted the tightest plug gauge that would drop through the lapped bore into all chambers so it's alignment is excellent.
The picture in the middle is the plug depth gauge used to make all the chamber mouth the same.
In the chamber ream picture four holes are reamed and two were not done yet to show the difference.

Nice! WRT the misaligned chambers, I guess that’s what forcing cones are for…

 

[M. De Land]

Nice! WRT the misaligned chambers, I guess that’s what forcing cones are for…

Yeah, the miss alignment bugs me but I have no answer for the fix when out vertically. Any suggestions short of a new cylinder? Accuracy testing should tell the story but I have had misaligned cartridge guns shoot quite well in spite of this with jacketed bullets. It should be interesting to see what soft lead balls do.
I guess considering every thing else being wrong on this gun I should not expect good alignment.

 

[Bad Karma]

I’d test by shooting full cylinders for group and then shoot similar numbers of shots from only the “good” chambers. The ball looks like it’s pretty deep into the forcing cone, I suspect the misaligned chambers won’t have as much effect as they might if the cone was shallower. Just a guess.

 

[Bad Karma]

Yeah, the miss alignment bugs me but I have no answer for the fix when out vertically. Any suggestions short of a new cylinder? Accuracy testing should tell the story but I have had misaligned cartridge guns shoot quite well in spite of this with jacketed bullets. It should be interesting to see what soft lead balls do.
I guess considering every thing else being wrong on this gun I should not expect good alignment.

It’s not popular but my opinion of the Belgian Colts isn’t very high, I’ve had one or two out of a half dozen or so. If you find a good one hold on to it as they do have significant collectors interest… I’ve had one very good one, complete with the box and paperwork. Traded it away for something better… damned if I can remember what the better thing was but that Centaure was a good shooter.