Percussion Hammer Cam (Divot)?

[Curtis Lee]

Looking for Information as to why this divot has developed on one of my 1861 Uberti hammer cams. I have two of these pistols one has the divot other does not.

 

[45D]

Looking for Information as to why this divot has developed on one of my 1861 Uberti hammer cams. I have two of these pistols one has the divot other does not.View attachment 293793

The bolt arm that rides the hammer cam (left one) is sliding off the side (creating the "divot") instead of off the front. It's one of the things that can happen when a new revolver isn't checked over before shooting/cycling and folks let them "wear in" . . . Things like this don't get better or fix themselves. This is where "knowing" what correct timing is supposed to be /sound like so you can fix it before it turns into a bigger problem.
At this point, I'd spread left arm out a little and see if it will stay on the cam longer. Can you post pics of the bolt?

Mike

 

[M. De Land]

Looking for Information as to why this divot has developed on one of my 1861 Uberti hammer cams. I have two of these pistols one has the divot other does not.View attachment 293793

It looks to soft to me and the bolt finger has gnawed into it. The profile, lateral tension and edge dressing of the bolt finger needs checked as well.
I'd replace it with one made of O-1 or A-2 tool steel which will never wear out if heat treated correctly.
I made and fit my last one friction/ press in tight with red loc-tite to secure it and it has worked very well. The front side face has the reset taper that needs to be file cut before it is heat treated and index , press fit back into the hammer.

 

[Curtis Lee]

Thanks for the replies. I will check into it further.

 

[Curtis Lee]

Here a couple of pictures. I will post my findings when I compose the text. That way maybe I can explain it understandably

.

 

[Curtis Lee]

HERE IS A PIC OF THE CYLINDER OVER TRAVEL MARKS. All notches have the same notch, All also have same marks on the leading edge notch.

 

[Curtis Lee]

I re-assembled the pistol with just hammer,hand,bolt and bolt spring. examined the bolt function several dozen times. On some occasion the works would lock up. I noticed the bolt would not drop allowing rotation.At this point the "working tang" on the bolt was under the cam (THIS IS WHEN"imo" the damage to the cam happened) but was bound by the bolt being pinched in that one particular cyl.notch. So I tuned the Hand with a couple of file strokes and a ruby polishing stone. Did this about four times. Finally the bolt would drop and not bind on the bolt tang(digging into the cam) because the the hand was not over driving the cylinder which locked the cylinder in that one tight notch.

I also polished the hammer faces that mate with working bolt-tang, (There was a high surface all along the hammer notch area)(NOT FLAT). Also polished the cam and it's shoulder.
Finally I did not tighten the bolt spring screw (Blood-Tight) Backed off about a 1/8 turn.

I will post any developments. Thanks for the help. Glad to answer any question or concerns.
THX Again.

 

[M. De Land]

I re-assembled the pistol with just hammer,hand,bolt and bolt spring. examined the bolt function several dozen times. On some occasion the works would lock up. I noticed the bolt would not drop allowing rotation.At this point the "working tang" on the bolt was under the cam (THIS IS WHEN"imo" the damage to the cam happened) but was bound by the bolt being pinched in that one particular cyl.notch. So I tuned the Hand with a couple of file strokes and a ruby polishing stone. Did this about four times. Finally the bolt would drop and not bind on the bolt tang(digging into the cam) because the the hand was not over driving the cylinder which locked the cylinder in that one tight notch.

I also polished the hammer faces that mate with working bolt-tang, (There was a high surface all along the hammer notch area)(NOT FLAT). Also polished the cam and it's shoulder.
Finally I did not tighten the bolt spring screw (Blood-Tight) Backed off about a 1/8 turn.

I will post any developments. Thanks for the help. Glad to answer any question or concerns.
THX Again.

That mark on the far side of the notch is late bolt lift often caused by to long of a hand nose trying to advance the cylinder before the hammer cam lifts the bolt high enough to clear the notch. My new 51 Pietta needed this adjustment on the hand nose to clear the notch before advancing.
It can also be caused by improper ratchet star fitting to the hand or out of spec notch milling as it may not occur the same amount on all notches. I've seen all three causes individually or some times in tandem with another. New cylinder fits will often reveal one or more of these problems that need corrected. I just had two of these problems on a new 62 Police cylinder fit.
Some times this can also be caused by to high a bolt dome which will be accompanied by an out of notch drag line .

 

[Curtis Lee]

THIS PISTOL did show out of notch drag line all the way around. I sharpie d the line to see if my work fixed it. So far so good. BTW My other 1861 (newer 2021)has not shown any of the problems with #1-2016. thanks for the feed back. Much Appreciated.

 

[M. De Land]

THIS PISTOL did show out of notch drag line all the way around. I sharpie d the line to see if my work fixed it. So far so good. BTW My other 1861 (newer 2021)has not shown any of the problems with #1-2016. thanks for the feed back. Much Appreciated.

Some of these guns I'm sure are late Friday and early Monday AM guns !
I'm reminded of my old boss telling me that years ago they got a brand new Cadillac in that had a knocking sound inside the door when driving down the road. This was an auto glass shop so they took the panel off the door and there hanging down from a piece of string with a nut tied on the end, free swinging with a note rolled up and poked through the threaded hole . They unrolled the note which read ,"There you rich SOB figure out where that knock is coming from" ! Now that takes a man with grudge on and going "WESTERN" !

 

[Curtis Lee]

M. De Land I have a question about setting up hand timing. Should I start a new thread or ask it here?​

 

[M. De Land]

M. De Land I have a question about setting up hand timing. Should I start a new thread or ask it here?​

M. De Land I have a question about setting up hand timing. Should I start a new thread or ask it here?​

I'm probably the worst about mixing up thread topics but as these are related I don't see what the problem would be doing it here. Several folks on here can give you some help on their opinion/ ideas of what will work.
I like hearing them all as I can learn new stuff as well as you can.

 

[Curtis Lee]

Would it be a good/advantageous method of pre timing a pistol if, One installed just the hammer & hand to determine how far the cylinder rotates in respect to the bore axis?

 

[M. De Land]

Would it be a good/advantageous method of pre timing a pistol if, One installed just the hammer & hand to determine how far the cylinder rotates in respect to the bore axis?

I've not done it that way because I want the spring load and fit tolerance in the completed gun as received from the factory to be present in the adjustment.
I think this might be a very good idea when fitting a new cylinder, getting the rotation lock up and tolerance movement dialed in then adding the ratchet fitting and hand nose length adjusted with the hand spring tension.
It's kind of like tillering a self bow as one floor tillers first, then adds a bit of tension with a long string adding brace height gradually , working out the hinges until finally scraping to full tiller getting both limbs to handle the stress (tension and compression) in harmony.
The same idea is necessary in gun work to balance all the adjustment factors to work with each other in harmony to accomplish accuracy and longevity.

 

[Joemolf]

The bolt arm that rides the hammer cam (left one) is sliding off the side (creating the "divot") instead of off the front. It's one of the things that can happen when a new revolver isn't checked over before shooting/cycling and folks let them "wear in" . . . Things like this don't get better or fix themselves. This is where "knowing" what correct timing is supposed to be /sound like so you can fix it before it turns into a bigger problem.
At this point, I'd spread left arm out a little and see if it will stay on the cam longer. Can you post pics of the bolt?

Mike

45D and Mike I know you’re are experts with these and was wondering if you know if that cam should be heat treated. I realize they are case hardened but the case hardening IMO doesn’t hold up on any of these critical parts from revolvers to rifles it’s one of the reasons I don’t use them as much anymore; get them dialed in and at some point something goes array and the timing goes out. Not end of the world stuff. I’ve purchased several replacement triggers probably have a few in stock including hands bolts springs and other. I know from experience you have to be very gentle with the bolt as I’ve snapped a couple applying the slightess pressure. Ias I mentioned I have purchased factory Ubertie hammers and the cams are different on all of them. I’m fine with that as I suspect these revolvers required a lot of fitting at the factory. What bothers me is once the case hardening is done they wear exceptionally fast. Do you and others that know the ins and outs of these revolvers address say the cam wearing issue. Then those garbage hands that come in the revolvers junk metal. Fortunately I discovered KristConverts makes a hand out of real metal that doesn’t wear out after a few uses. Other examples would be my Ubertie 1873 rifle the sears on those are so soft that after the case hardening wears off you can end up with a rifle where you can feel the trigger pull becoming softer and softer to the point you can blow the trigger and the gun will fire. Same with the lifter cam on the lever once that case hardening wears away or is purposely removed they go south really fast. Can these revolvers be made to function where you can get say 100 shots out of one following normal cleaning and lubing. I have a few of these and I can’t imagine from the replicas that I own that many must have struggled with them back in the day. I have two colt gen 2s I believe an 1851 and 1860 are they any better there like a piece of rock candy that’s not for eating but looking at LoL. Back to the dimple I would think they are pressed in and could be replaced with a hardened one do you do work like that. The gen 2 colts i thare or were made by Ubertie.

 

[Joemolf]

45D and Mike I know you’re are experts with these and was wondering if you know if that cam should be heat treated. I realize they are case hardened but the case hardening IMO doesn’t hold up on any of these critical parts from revolvers to rifles it’s one of the reasons I don’t use them as much anymore; get them dialed in and at some point something goes array and the timing goes out. Not end of the world stuff. I’ve purchased several replacement triggers probably have a few in stock including hands bolts springs and other. I know from experience you have to be very gentle with the bolt as I’ve snapped a couple applying the slightess pressure. Ias I mentioned I have purchased factory Ubertie hammers and the cams are different on all of them. I’m fine with that as I suspect these revolvers required a lot of fitting at the factory. What bothers me is once the case hardening is done they wear exceptionally fast. Do you and others that know the ins and outs of these revolvers address say the cam wearing issue. Then those garbage hands that come in the revolvers junk metal. Fortunately I discovered KristConverts makes a hand out of real metal that doesn’t wear out after a few uses. Other examples would be my Ubertie 1873 rifle the sears on those are so soft that after the case hardening wears off you can end up with a rifle where you can feel the trigger pull becoming softer and softer to the point you can blow the trigger and the gun will fire. Same with the lifter cam on the lever once that case hardening wears away or is purposely removed they go south really fast. Can these revolvers be made to function where you can get say 100 shots out of one following normal cleaning and lubing. I have a few of these and I can’t imagine from the replicas that I own that many must have struggled with them back in the day. I have two colt gen 2s I believe an 1851 and 1860 are they any better there like a piece of rock candy that’s not for eating but looking at LoL. Back to the dimple I would think they are pressed in and could be replaced with a hardened one do you do work like that. The gen 2 colts i thare or were made by Ubertie.

Thanks

 

[Joemolf]

At one point I purchased a half dozen spring s and buttons, I was going to try my luck with drilling the hole so to set the hand spring tension. I’m sure they will show up when Im dead and get tossed because they have no idea what they are. Maybe those recommendations are paise today. Does not matter I just don’t have time for the revolvers I enjoy flintlock more. Especially because I found what I consider material flaws got old after a while.

 

[Curtis Lee]

I may have not explained the process completely. The method I used was the complete gun assembled, less the bolt&spring,trigger. just see how far the hand was rotating the cylinder past zero bore axis. I follow your description. I was trying to sort of get a base line before modding the hand or anything else.

 

[45D]

Would it be a good/advantageous method of pre timing a pistol if, One installed just the hammer & hand to determine how far the cylinder rotates in respect to the bore axis?

CL, "timing" needs to be done with "all parts" involved.
The first step in "setting" correct timing is to establish the correct hand length. This means the bolt will have to drop ( drop denotes the arm falling off the cam which means the head of the bolt "drops" onto the cylinder) BEFORE cyl lockup.
That means everything that is going to happen has to happen from hammer down till full **** (length of cycle). The correct length of the hand is when cyl lockup and full **** happens simultaneously ( sounds like one click). If lockup happens just before full ****, the hand is too long. Obviously if lockup happens after full ****, the hand is too short. Stretching the hand is for another thread . . .
Hopefully, the hand will be slightly long so you can slowly shorten it by sanding the top on a flat surface with 220 paper (keep top angle) or maybe, it'll be just right ( good luck ! ).

Once you have the hand correct, you're almost done! The next thing is "bolt drop". The bolt should "drop" (onto the cyl) at least one bolt width before the notch. If there is an "approach" (lead), anywhere in it is ok as long as it still meets the minimum stated above. Adjusting the drop involves removing material at the end of the bolt arm. I'll stop now and look for some pics.

(Oh, but once you're there, you'll have "textbook" perfect timing.

 

[M. De Land]

I may have not explained the process completely. The method I used was the complete gun assembled, less the bolt&spring,trigger. just see how far the hand was rotating the cylinder past zero bore axis. I follow your description. I was trying to sort of get a base line before modding the hand or anything else.

I like and set the timing up for early bolt drop to dampen lock up inertia into the notches.
I also prefer and set up the hand length to push a bit past bolt lock up as this allows some wear in length without straining anything.
It must be remembered that at lock up the hand is past the 90 degree ratchet tooth contact and is into the back angel of the tooth. I want them snug with out any jamming pressure.
Time to go put some glass in a loader so I'll sign off.