What a gem you have been given Delmar! It'll learn ya bout the Colt Open Top and that will be knowledge well served in the future.
There are more ways to fix up an old loose Colt than Cotter had little liver pills. There are some ways that are better to use than others. Like welding yer wedge to be wider. That's a good fix but.....ifin you welded a spot of weld into the front of the arbors wedge slot you could file fit a "NEW FACTORY WEDGE" and then be able to replace at will in the future without re-welding yer wedge. You'd just send for a new factory correct wedge.
That fix with the screw on the end of the arbor that can be filed to "Bottom the arbor" in the barrels hole is a good one. I'd say it would be better to screw the screw into the arbor till it butts against the arbor and then carefully file the screws head to be a perfect bottomed arbor fit. It's difficult to file perfectly and the use of a lathe to get the end of the screw head all perpendicular to the centerline of the arbor would be nice. Not imperative but nice.
Dropping washers in(fender washers from the hardware store are best because of the thickness and the smaller hole in the middle) is a good enough fix to bottom the arbor in the barrels arbor hole. You can drop one washer in filed on the outside circumference to be a slightly tight fit in the hole so they don't drop out and they can still be pulled out with something like a dental pick if cleaning in there is needed or future adjustments are needed. I've done the "washer fix" to bottom arbors. I'd drop a washer and test at the frame/barrel junction and repeatedly stone the washer flat on a stone till the barrel fit up to the frame with a few .001's space there(doesn't hurt thing). The space is left there so the "seating in" of the parts takes place from tapping the wedge in. A small steel hammer tapping the wedge in lightly gives off a sound that you learn is the sound of the taps the hammer makes on the wedge when the arbor is bottomed and the barrel is installed "tightly" as it should be with the arbor bottomed. The taps are hollow sounding till the arbor is getting bottomed and then the sounds of the taps get solid sounding and higher pitched. Try it you'll like it. No better sound than the little hammer tapping a wedge on a bottomed arbored gun and making those high pitched solid sounds to the taps.
Just light taps though.
Anywhooo....you could have yer Buddy mig weld the washers to the end of yer arbor once they are sized to fit well. Patience is the key to botoming an arbor.
Of course there is a simple way to fix er that ends up as good as a bottomed arbor if not better. That's to fit the arbor in the barrels hole with "no space" when the arbor's in the hole. Like a kinda twist and push on fit. No space in the barrels arbor hole when the arbor is in it is actually the best fit. You can still get the barrel off easily by using the loading lever plunger against the space between the chambers of the cylinder as a push point to put the plunger against to lever the barrel off.
Fit the arbor to the barrels hole with no space? Easy. Just have yer Buddy weld a small spot near the end of the arbor on the top of the arbor and another spot near where the barrels hole starts,on top the arbor...just about where it would be just inside the beginning of the barrels hole. If you take the time to file and polish the "bumps of weld" to be a tight enough fit into the barrels hole where you kinda twist the barrel some to get it on the fit will be "the best" and better than a bottomed arbor. If you do bottom the arbor first then put the "bumps of weld" on the top of the arbor you will have the proverbial "prime fit" to yer barrel on the arbor. It makes a difference in whether the gun shoots "prime" too. Tight barrel usually always means a decent shooter. Even a brass framer can be a tack driver. Makes shootin fun. Anywhooo...the weld "bumps" a top the arbor makes for a real nice fit even without the bottomed arbor. (the bumps get filed and polished so they are barely visible)Yer choice.."bumps on top the arbor" or "bottomed arbor" or "both" fer prime fit.
One side note...ifin you have a gun with a fairly loose fit to the arbor in the barrels hole and.....the gun shoots left or right or high or low you can....
Adjust the point of aim by placing bumps on the arbor where the arbor goes in the barrels hole within the tolerances of the "loose in the hole" arbor will let the barrel move a bit on the arbor. Standard fit to give the tight fit like an easy bottomed arbor would be to put the bumps on the top of the arbor. That's not paying any attention to point of aim except probably just get the barrel pointed straight down the centerline of the arbor if the arbor hole is parallel to the bore. Just a thought as a side note about adjusting point of aim with bumps of weld on the arbor to move the barrel a little. A little goes a long way. The bumps ,naturally, are placed to move the barrel the right way to correct,or help correct, the point of aim/point of impact of the shots fired.
Starting at the right place to fix the gun would be to first tighten the arbor in the frame where it screws in. Usually ,unless the gun was shot when it was loose a lot, the original lock pin is just getting loose. Tightening it isn't too difficult. You need a flat faced punch with straight sides,not tapered, the size that will actually fit "in" the hole where the lock pin is seated. You may have to grind a tapered punch to be a good fit and be flat faced.
Take the gun apart and use just the frame with the arbor in it. Put the end of the arbor on a flat solid steel surface. Solid steel. Use the punch to smack the lock pin pretty hard. The object is to "bump up" the diameter of the lock pin so it is tight in the hole. Putting the end of the arbor flat on a solid steel surface will help insure the shoulder of the arbor where the threads end is tight against the frame. That's important. The shoulder of the arbor has to be tight against the frame. One way to insure the arbor doesn't go crooked when the lock pin is tightened is to do as was mentioned above but put the barrel on the frame periodically to make sure it is going to fit and the arbor hasn't gone crooked.
Put the barrel on the gun...pad the steel surface with thin cardboard or leather and with the barrel muzzle flat faced against the padded steel surface strike the punch and "bump up" the lock pin. The pin being tightened can't move the arbor crooked much if the barrel is on the frame. Don't put the wedge in to hold the barel since that pulls the arbors shoulder away from the frame. The object is to bump up the lock pin to tighten the arbor and drive the frame down at the same time against the arbors shoulder for a good fit. Easy.
On a steel framed revolver if the lock pin isn't enough to tighten the arbor into the frame I've used weld in the lock pin hole after the lock pin was drilled out. You know...when the arbors hole in the frame has been deformed from a lot of shooting after the arbor became loose. That deforms the hole and the threads. If there's some thread left to tighten the arbor and the arbor needs some help to stay tight then welding in the lock pin hole works real well. Actually if you lay a file on it's side and file a groove across the arbors back end where the groove goes into the frame also and then have that groove welded over and filed smooth that guns arbor will never loosen up again.
The brass framer can have brass braised in the same fashion as the welding was done to a steel framed gun. The brass framer just needing brass braised instead of welding. When the end of the arbor is welded in any fashion "the barrel has to be on the gun" but....the wedge has to be barely put in the slot so to "not pull the arbors shoulder away from the frame". The arbors shoulder needs to be against the frame. Side note....drilling and tapping the lock pin hole and putting an allen head screw in the lock pin hole and cinchin it up tight pulls the arbors shoulder into the frame and holds it there and tightens the arbor pretty well. Gunsmiths like to do that allen head screw fix fer the lock pin since they know how nice it is to get a gun to fix that has that allen head screw feature to it.
One note I'd like to make is...when filing the end of an arbor to bottom it or spacing washers in the bottom of the arbor hole in the barrel or however you bottom the arbor in the hole there's a trick to get the arbors end flat against the bottom of the hole. Use Prussian Blue from Brownells or some form of "color" on the end of the arbor. That can tell you if there's a high spot to file down. You can see where the end of the arbor hits the bottom of the barrels hole. It's like you file the high off where the color shows it untill you start getting blue or color around the whole circle on the end of the arbor. Like inletting parts into wood. You find the high spots with inletting "color" and file the color till you start getting color to the hole circle around the end of the arbor. Then at a point the color can be seen to squish away from the areas where the parts mate and sort of crush fit against one another. The crush fit spots show "no color" because the color is moved out of those spots by the parts fittin real tight there. That's what you want to see on the end of the arbor. A "no color" ring around the end. Sometimes just on the outter edge around the end of the arbor and sometimes a widder ring of "no color" depending on the shape of the bottom of the barrels arbor hole. The hole need not be perfectly flat and some are concave shaped at the bottomof the hole but that's alright unless you're a real perfectionist and want to bottom the hole with an end cutting end mill on a milling machine. It's alright even if just the edge of the arbors end contacts the end of the hole.
One thing to watch for if you're looking at the end of the arbor and using color to see if the whole circumference of the arbors end is contacting the bottom of the hole in the barrel should be mentioned.
When the wedge draws the barrel on with the tremendous force wedges can generate something happens when there's even the tiniest amount of space in the barrels arbor hole when the arbor is in it(most all the time this is true...there's space in that hole with the arbor in it). The wedge can draw the barrel back with all that force and get the barrel to cant back and slightly downwards at the beginning of the barrels arbor hole. The wedge will get the force put on the upper part of the end of the arbor and get the barrel to cant backwards and down at the beginning of the arbor hole in the barrel. That makes a perfect mating to the end of the arbor and the bottom of the barrels arbor hole imperfect with the upper end of the arbor making the contact at the bottom of the hole and the lower part of the end of the arbor not making contact or making lighter contact.
The barrel tries to cant back and downward even with a bottomed arbor if there's any space at all to the fit of the arbor in the barrels hole. If the space is small like on the Pietta Colts the movement of the barrel canting is negligible but still there. If the space is large or small the barrel still cants backwards and down some and messes up a perfect fit to the arbor at the bottom of the barrels arbor hole. If the mate or contact to the end of the arbor and the bottom of the hole is at least 1/2 to 2/3rds contact on the upper part of the end of the arbor against the bottom of the hole it's still a good fit......and the way most all the guns with a bottomed arbors and a less than perfect fit to the arbor in the barrels arbor hole actually are when the wedge is tight. Even your guns bottomed arbor since there's probably space in the barrels arbor hole whenthe arbor is in it.
There's a way to offset that mechanical anomaly concerning the fit and forces emmitted to the arbors end and the bottom of the arbors hole in the barrel and the space at the beginning of the barrels arbor hole that lets the barrel cant a small amount even with a bottomed arbor. Don't dispair.
A simple spot of weld on the top side of the arbor positioned right inside the beginning of the barrels hole and file fitted to make a "no space" there is the simple solution. The bump is filed and polished and is hardly visible but...it does a lot towards keeping the barrel from canting and making the shots go higher than they need to and making the end fit of the arbor to the bottom of the barrels hole stay flush contact around the full circumference at the end of the arbor...as most imagine it is and stays. Actually it only does that when there's no space to the barrels hole when the arbor's in it. That image of a perfect contact full circumference mate fit at the end of the arbor and the bottom of the hole is false though if there's any space at the beginning of the barrels arbor hole at the top side of the hole. Most of the time it is imagined the arbor just goes to the bottom of the hole and meets it full contact and stays that way when the wedge is inserted. Actually that space at the top entry of the barrels hole and the arbor space will close up and the barrel moves a small amount even with a bottomed arbor when the wedge emmits all that force. That space will close until it's got the barrels entry to the hole in contact with the arbors top side. Anywhooo..that little "bump" welded to the arbor to close the hole at the top at the beginning of the barrels arbor hole does plenty to insure the end of the arbor stays flush contacted to the bottom of the barrels hole. A "race Colt" would have a lathe turned arbor fit that the barrel has to be twisted and pushed a little to get on it since it would be a near perfect fit just loose enough to get the barrel on. That is an arbor with as little space as possible to the fit of the arbor in the barrels hole.
A "close second method" and a much easier way is to spot and fit a coupla welds at or near the "top end of the arbor" and at the place where the bump will be at the "begining of the arbors hole in the barrel at the top side of the hole". Then you know...the end of the arbor stays flat flush contacted at the bottom of it's hole. Side note...you'd hope the cylinder was loose enough on the arbor to still go on the arbor when the "bumps" of weld are there. Usually the cylinder will go on. Most of the time the end of the arbor where the barrel goes is a little smaller than the part of the arbor where the cylinder rides. You'd be wise to check that feature so you wouldn't be cussin me when the bumps tighten the barrel to the arbor but..the cylinder can't go on if you have an arbor the same diameter all the way to the end. ha ha ha Evidence of the barrel canting even with a bottomed arbor can be seen at times when there's an impression imprinted to the end of the arbor from the force of the wedge and anything that can imprint at the bottom of the barrels hole. Drill lines,the edge of the hole that's at the bottom of the hole when some of the bottom is concave ect.ect.ect. or any irregularity at the bottom of the barrels hole. Side note.......I've used a simple shim made of copper or brass that's inserted in the arbor hole with the barrel where as the shim is on top the arbor where the space usually is instead of using a little "bump" of weld. The shims work real well to tighten the barrel to the arbor and they can be simply cut with scissors to fit. Left a little wide and tight they can be form fitted(since they are soft metal like copper) by tapping the barrel on with the shim in there with a rubber hammer. The shims go over the top of the wedge slots and are relatively thin laying atop the arbor when the barrel is inserted on the arbor. A screw driver can be uased to keep the shim from moving backwards whenthe barrel is inserted on the arbor. Of course the shim has to be the right thickness to go in the space at the top of the barrels arbor hole. Piettas take a real thin shim and Uberti's can take shims made of beer can metal at times the space is so large. Just don't try to get a shim in there with the barrel when the shim is too thick. The approx. proper thickness and the shim cut narrower if it seems too tight and wider if the shim seems too loose. You just cut the shims a little wide and try them and if need be cut them more narrow till they go in but go in tight. After awhile(many many shots fired) thge soft metal shim is repalced since it gets beat from the force and flattened. It's easy to insert the shims once you get the hang of it. The shims keep you from having to weld any bumps to the top of the arbor. A barrel tight on the arbor always is more consistantly accurate. If the chambers are the right size on your gun for the rifling grooves in the barrel and the arbor fit is right and bottomed and the barrel tight your COLT can keep right up with your REMINGTON target shooting. Naturally you'd do things to get the Colt to shoot to point of aim as you probably did with your Remington or any cap&baller you have. Naturally you'd use lube pills or wool wads saturated with some lube right down atop your powder charge under your balls to keep the barrel clean enough to keep accuracy consistant. Naturally you'd make a lube that was wax/lube in the right proportion to be compatable with the load chain with the lube pill or wool wad on top the powder under the balls. Two thirds wax and one third lube is a good combo. Lube/wax stiffer than what you'd use in conical bullets. I always say the lube pills have to be soft enough to squish between yer fingers but stiff enough to handle. That stiffer than conical bullet lube for blackpowder lube makes it possible to put it right on the powder under the balls where it canactually do whatit's there to do....... keep the barrel and chambers free of blackpowder fouling and keep the hjole in the center of the cylinder protected from fouling going in. Better to have lube/wax go in and block that space each shot in front of the blackpowder fouling. Better to have the lube/wax go down the barrel in front of the fouling.
Anywhoo.....you can use all kinds of tricks to "Kitchen Table Gunsmith" one of those old loosened up, shot out ,dirt rollin messed up, abused and tortured old Colts.
One trick I use and promote for a brass framer or old beat to death steel framer ,new or old brass framer, is to use a "narrow rimmed bushing" from the hardware store or auto supply store usually sized at 7/8ths X 1 3/8ths 14 gauge to repair or protect the ring on the frames recoil shield that keeps the caps off the frame so they don't chain fire against the frame. The ring gets smashed in on six spots when the cylinder recoils into it each shot after awhile especially onthe brass framers. The caps can then get to the frame of a beater Colt and chainfire. Making a little thin steel backplate and soldering it(brass framer or steel framer) to the frame around the recoil shields ring makes for a good lasting fix especially to a brass framer Colt. Naturally you fit the bushing around the recoil shields ring and cut it away where need be to fit and to be compatable. You know..you don't want it across the hammers recess slot in the frame so the hammer hits it or cover up the loading port side where you put on yer caps. Anyway.....with the bushing in place ,and becoming a little steel backplate, the nipples need cones shortened and the safety pins filed away. Load only five and keep the hammer on the empty chamber. The bushing just makes a wide little steel backplate to help the poor little brass or deformed steel ring on the recoil shield of an old Colt. It'll help any brass framer last as long as you do ifin you just fire standard loads in the gun(not neccesarily light loads either). The steel back plate will enable the gun to withstand heavy charges and even withstand hot 777 loads but...not forever and why get caried away. Standard loads like 25gr. FFFg for a 44 ball and 22gr. FFFg for a 36cal. ball are plenty of "whomp" fer a cap&baller and...the thin steel backplate around the recoil shields ring will make the gun last. Remember to shorten the cones on the nips with a stone or you'll get chain fires.
One of the most satisfying feelings is to pick up and pull the hammer on an old beater Colt gun you tuned up and tightened up especially if you have er shootin point of aim/point of impact. That will be one of the "favorites" in yer collection of cap&ballers.
See yas pards!