I fergitted to mention about a remark concerning the bolt legs bevel on the backside that rubs/rides on the surface of the cam on the hammer. It seemed it was inferred that that bevel has something to do with timing of the bolt and all.
Well......that bevel is there to let the bolt leg ride back onto the surface of the cam with an harmonious smooth contact. That's all...nothing to do with timing the bolt. Most all that is done by shortening or lengthening the bolt leg that rides the hammer cam. Longer and the bolt stays on the cam and off the cylinder longer and shorter the bolt leg stays on the hammer cam a shorter time and hits back to the cylinder sooner.
The cam sometimes has an edge at the bottom the bolt leg can snag on and hamper the action working smoothly. The lil flat bevel on the back of the leg that rides the cam eliminates the snag.
Cams on some of the older guns are separate pieces or parts. Most anymore are one piece with the hammer being cast as part of the hammer.
Standard fare with some tune jobs is the person wants a harder cam. At times the cam is too worn to be operative. In a case like that the cam can be changed out whether it's integral with the hammer or a separate part. Soften the hammer when it's got the integral cam.....dot the center of the old cam with a punch to start a pilot drill and drill straight thru the hammer. The new "bought" or fabricated cam will go in the hole later. The cam that is discarded is milled or filed off the softened hammer. The hole that was drilled is enlarged to accomodate the new cam. It's inserted with a pressed fit in the hammer making sure it's turned the right way to work the bolt leg. If yur new cam is pre-hardened you can leave it as is or soften it before insertion whatever you like according to what tool steel is used to make one or what the cam that was "bought" is like.
After the fitting the cam the whole hammer is casehardened once again. Use of a hardening compound like the old Kasenet(has a new name now...ask at Brownells) is standard fare with the "Kitchen Table Gunsmith". There are instructions with the compound. I used the instructions at first but modify them anymore.
I bury the whole part....hammer,frame,trigger ect.ect. in the compound all in a small cast iron fying pan sitting on a propane single hot plate or burner(or whatever it's called). With the burner I have on full heat and a propane tourch hitting the pile of compound from above I turn it red like bubbling lave for at least 15 minutes. Usually I try to make it to 20-30 minutes of pure red compound with the part inside being red also. Try to stay at black cherry color or cherry and avoid the orange that's too hot.
Once the chosen time is elasped the part is picked out of the compound and thrown in oil or water. Both work. Then the part is hard on the outside and with some metals hard inside to a degree also. Depends on carbon content. The Italian hammers don't seem to be "high carbon" but I'd say there is some carbon in them and they get harder clean thru. Some hammers are actually too hard to drill a hole thru and they need softened. Softened....heat to black cherry or cherry color and let the part air cool where there's no breeze. Then it's dead soft.
Once the part is quenched it is now hardened with an "en-cased in carbon" thus the term case hardened. If you thunk you started with a part with more than "low carbon" content then tempering in an oven at 375 degrees for two hours puts the "tough" to the under-lying metal letting the carbon on the outside remain hard enough.
When old hammers are "spiffed up" with modifying back to original with welding or filing or new cams or whatever they need hardened again. Triggers and hands can be hardened too and anything done to the hammers sear or the trigger means rehardening the parts to insure "hair trigger" isn't premature as it's a safety concern. Polishing included. Who knows how many .001's deep the original case hardening was?
It's a personal decision as to whether of not hardening the hand is needed. I'd rather not harden the hand as much as change it out to a good tool steel that's got enough hard to it before "hardening". I'd rather later change out or repair a hand rather than change out or repair the rear of a cylinder.
if a person wants to get a little deeper into case hardening they can get the bone and wood charcoal from a gunsmith supply and use a wood fire to case harden the real old way.
Not hard to do. Looks cool too. Just don't harden with the metal getting more than red cherry. The metal crucible with the parts inside with bone and wood charcoal in the fire at night tells the story as you can see it and assume the parts inside are the same color. Heat fer awhile then quench in cool oxygenated water with the parts close to the water so air doesn't hit them much. Just close enough to drag a little oxygen down with the parts. Drop about an inch or two from the water. A little nitrat in the water helps get more blue color to the case hardened parts.
When a hammer is fit right it doesn't attain any where nears the battering people mention. Usually the hammers that aren't dry fire safe are a little too long in the nose and just need fitted right. Fit so when the cylinder is fully forward the hammer nose is not able to batter the nose on hitting the nipple cone on a percussion open top. On the cartridge the hammer shouldn't be able to hit the housing the firing pin is in....just come close. The firing pin needs to be the right length too though.Just long enough to give the primer the dent it needs and no more and that needs to be so many .001's only on the side that's hit by the hammer.
The hammers should stop on the frame before they can batter the other parts. Know what I mean?
I have to reply to that good looking guy....Old Fluff?
I have seen plenty of original Colts. You know....our opinions about hammers hitting backstraps has crossed paths before. I figure mines more logical mechanically speaking. When you talk of hammers battering the parts....like the hand on the cylinders index ratchets or the bolt hitting the cylinder too hard you ain't thunkin it thru all the way I'd say. Think about it.....working the action fast will send the hand into the rear of the cylinder and spin the weight of the cylinder into the bolt that stops it with lots of force especially when the cartridges are in it regardless whether or not the hammer stops at the backstrap. All the force needed to batter the parts is there even when the hammer stops at the backstrap. It all starts and all the force is applied before the hammer can hit the backstrap. Sure a person can pull hard enough too really over do it with the hammer not hitting the backstrap but that's not they way a person with any sense works their gun. Anyway working a gun "fast" with the hammer hitting the backstrap or not the difference between "hammer hits the backstrap" or "hammer doesn't hit the backstrap" is almost negligible unless a gorilla is working the gun.
What isn't negligible is the fact that if a gun is tuned to have the action stop right as the hammer hits the backstrap any wear put to the hand will necessitate having the hammer have to go rearward further than it's capable since the backstrap hits it and stops it. The gun thus being inoperable with a small amount of wear.
Anywhoooooo......the original Colts I've seen and worked in my hand that hit the hammer on the backstrap seemed to be well worn and just barely able to have the action work.
If I saw some documented historical facts of evidence to back up yer claim then......I'd join the fan club and be a "hammer stops against the backstrap" believer myself. I still wouldn't tune guns like that though unless an Hombre I was helping wanted that specifically.
If ole Sam Colt back in the day made his guns coming out the door like you say.....I'd tell him that was a design defect to be heaped into the pile when it comes to the good ole "Open Tops".
Anywhoooooo........you may be right about the way Colt did his guns...I ain't sure about why he did this or that with them and I'm not an "expert" neither. I do know mechanical logic tells me there's enough force either way....hammers hit or don't hit the backstrap at the end of the action cycle...... to damage the guns from too much "hard fast pulling" of the hammers. I might talk to the Hombre at Peace Maker Specialists and see what he says about the subject. I'd keep it to myself though since I'm talked out on this "backstrap and hammer" thing. You win...I give up.....and I ain't as good lookin neither.
I do have a really handsome hound pup that I'd bet money is almost as good lookin as Brad Pit.
I just re-tuned my old Paterson awhile ago. In the end I pull the hammer as fast as I can move my thumb many times to test the action. It skips a beat it goes back on the work bench. It worked it's hammer and cylinder as fast as most anyone can move a thumb and it worked perfectly. I don't have the hammer hitting the backstrap....for if I did I'd need such a short hand and long trigger to do that I don't know if the action would even work with them in there.:banghead:
Anywhooooo Old Fluff......now I'm going to want to research this backstrap hammer thing and waste my time just to satisfy my curiosity. I have to fix the old beater trucks frame and go cut some wood and all chores like that.:banghead: Maybe some of the other Hombres here that have their curiosity aroused would lend a hand to research this hammer hittin the backstrap thing. I may be thunkin wrong on how ole Sam Colt did things.
One thing I figger I know....the cylinders were harder on the old Colts than on the new replicas. They used iron at first and then that Sheffield silver nickle(or whatever it was nicknamed) new steel after the Walker debacle with cylinders blowing a cork. The steel used is one reason the old Colts don't have all battered lookin cylinders. Sorta like the new modern revolvers that are higher quality don't get battered cylinders. You know ....Rugers,S&W;s and Colts ect ect. including the Uberti's cartridge conversion models and the SAA types.
Salute!
