Diagrams - How to Adjust the Colt Lug Joint

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Holy moly ! Another consideration ! Thanks, if I run into it I'll know what to do ! Is this how gunsmiths of old sighted them in ? Were they adjusted at the factory ?
 
Gordon said:
Holy moly ! Another consideration ! Thanks, if I run into it I'll know what to do ! Is this how gunsmiths of old sighted them in ? Were they adjusted at the factory ?
Click to expand...

That beats me Gordon, some were probably trued at the factory better than others.
One guy with an original 1860 said that he sets his barrel /cylinder gap using his wedge which could mean that his arbor isn't perfectly matched.
I wonder if the critical mating surfaces can wear, such as the contact at the tip of the arbor and the bottom of the arbor hole, the lug and frame junction, and any of the wedge mating surfaces.
And that's assuming that the bore is straight in the blank after the barrel is finished.

I'm guessing that these adjustments are more about shooting at longer range, and probably won't be noticed much at short distances.
With today's modern production methods, you'd think that the barrel lug & frame interface is relatively true from the factory., unless shimming the arbor actually does change the trajectory.
Even then, most folks probably sight in at 25 yards and are satisfied to simply adjust the hammer notch for that distance, and don't shoot much past that.

However, this could be a sticking point if wanting to install or shoot with those long range Dragoon express sights that were recently discussed.
Then each leaf may need to be adjusted for windage or the lug would need to be trued to try to accommodate the sights, or else Kentucky windage would be needed if wanting to use them for longer distances.
Each gun would have it's own shooting characteristics unless production methods regulate some of the variables.
I just found the diagrams to be interesting.

I wonder how 45 Dragoon does it, if he actually shoots the gun when determining that it needs a correction and at what distance.
If I post one of his previous quotes on the subject then maybe he will reply.

45 Dragoon said:
Mike, does a spacer always correct a loose cylinder issue?
In some cases, doesn't correcting the clearance involve more than simply correcting the short arbor, but can require correcting the fit of the interface of the barrel lug to the frame?
Can anything else be involved with fixing a loose cylinder?

Yes, an out of spec frame or out of spec (short) cylinder would need the frame /barrel lug surfaces addressed (or hopefully a replacement cyl). Typically you can remove the locating pins from the frame and lap the frame into the barrel lug (frame is harder than the barrel) to cure the "long frame". Makes for a nice fit (if /when needed) but it is very rare occurrence. Another problem that needs to be addressed from time to time is a long forcing cone. Obviously, removing material there is the fix.

Since a corrected arbor denotes the bbl /cyl clearance, I guess you could say a spacer ( or welding) is always at least "part" of the fix.

When testing ignition in the shop, I always point the barrel down just to make sure the cylinder is as forward as possible. A fail to fire means too much hammer /nipple clearance. Of course, nowadays I set them all up for a positive contact . . . they MUST go bang!!!
Mike
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--->>> https://www.thehighroad.org/index.php?threads/need-help-colt-won’t-fire.869368/page-5#post-11530606
 
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I hate to display my ignorance, but I’m not sure where the shim is supposed to be placed. Does anyone have a photo or more detailed diagram? Thanks.
 
So, if my Walker shoots high, I should hone down the section of the barrel right where the pins go in?
 
kell said:
So, if my Walker shoots high, I should hone down the section of the barrel right where the pins go in?
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No, absolutely not.
The Colt sights were designed to shoot high because the effective combat range of the gun is about 100 yards.
Most all Colts will always shoot high unless a higher front sight is installed to lower the point of impact.
The diagrams are only informational for the purpose of showing how to correct a lug joint that's out of square with the frame.
Normally a person simply corrects their arbor length which in part can affect the size of the barrel - cylinder gap.
From there sight adjustments can be made.
Otherwise the lug joint would need to be carefully evaluated to see if there's truly a problem.
Some expert gunsmiths make those adjustments if they are getting paid to do it, such as when the barrel - cylinder gap is too large.
Otherwise it's cheaper to install a new front sight and see how that works out.
Modern manufacturing methods probably make most of the lug joints square from the factory.
 
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arcticap said:
No, absolutely not.
The Colt sights were designed to shoot high because the effective combat range of the gun is about 100 yards.
Most all Colts will always shoot high unless a higher front sight is installed to lower the point of impact.
The diagrams are only informational for the purpose of showing how to correct a lug joint that's out of square with the frame.
Normally a person simply corrects their arbor length which in part can affect the size of the barrel - cylinder gap.
From there sight adjustments can be made.
Otherwise the lug joint would need to be carefully evaluated to see if there's truly a problem.
Some expert gunsmiths make those adjustments if they are getting paid to do it, such as when the barrel - cylinder gap is too large.
Otherwise it's cheaper to install a new sight and see how that works out.
Modern manufacturing methods probably make most of the lug joints square from the factory.
Click to expand...
Thanks for the insight.
 
Whats up with the guys on youtube that just put in and take out wedges with their fingers? If its loose as that doesn't seem like it would stay or last.
 
TWC said:
Whats up with the guys on youtube that just put in and take out wedges with their fingers? If its loose as that doesn't seem like it would stay or last.
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I have a Walker (Uberti), and an 1860 Army (Pietta). If I tap in the 1860, I'll probable have to tap it out - it's tight. The Walker's tight but it won't tap in so tight I have to tap it out. The wedge screw stops it just short (another couple thousanths and it would be real tight.) Cylinder gap on both is .006.
 
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arcticap said:
No, absolutely not.
The Colt sights were designed to shoot high because the effective combat range of the gun is about 100 yards.
Most all Colts will always shoot high unless a higher front sight is installed to lower the point of impact.
The diagrams are only informational for the purpose of showing how to correct a lug joint that's out of square with the frame.
Normally a person simply corrects their arbor length which in part can affect the size of the barrel - cylinder gap.
From there sight adjustments can be made.
Otherwise the lug joint would need to be carefully evaluated to see if there's truly a problem.
Some expert gunsmiths make those adjustments if they are getting paid to do it, such as when the barrel - cylinder gap is too large.
Otherwise it's cheaper to install a new front sight and see how that works out.
Modern manufacturing methods probably make most of the lug joints square from the factory.
Click to expand...
By the way, when I say high, I mean about a foot at 25 yds. Probably right on at a hundred, but I don't shoot pistols 100 yds.
 
Normally the frame and lug are fine. It's usually after someone has "tinkered" with it that it needs attention. So, I've only had to "correct" that joint very few times. Correcting the arbor to a .0025" - .003" bbl / cyl clearance rarely makes for an elevated barrel of any significance. The main thing is having the same revolver every time you assemble it ( driving the wedge in). Correcting the sight picture on that setup gets you on target and keeps you there.

Mike
 
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