1868 Sharps Loose Barrel

[VenisonRX]

Long time lurker first time poster. Picked up a sharps conversion carbine that appeared to be in good condition minus no bluing left on the barrel and a perfect bore. It’s a 3 grove Springfield relined barrel in 50-70 and slugs at .515

Got it home wiped it down with some rem oil and a few days later took the fore end off to check out the lever spring and do a quick chamber cast when I noticed the barrel turn slightly. It was lined up on the witness mark but I was able to unscrew the barrel by hand.

Looks like some oil had seeped into the threads and allowed it to loosen. I’m able to turn it about 1/16 in past the witness mark to hand tighten it. Anyone here see this problem before or might know what’s happening? A quick look at the action and the threads with the barrel off doesn’t show any signs of cracks or wear and it screws in solid without any play or wiggle. Would like to get this thing shooting again with some black powder loads since otherwise it’s in great shape.

This is my first original sharps so I’m still learning about them. I also have a Shiloh carbine in 45-70 that I live to shoot. Thanks for any help.

[john.k]

Loctite nutlock.....the pale blue stuff......its what Rossi use to set the 92 barrels when they dont index..............if you dont fancy that,then a bit of teflon pipe tape might be OK,for a while......Its extremely unlikely oil has loosened you barrel.........far more likely its been swapped ,and the new one happened to have a loose thread.............certainly not terminal.............years ago I made a Lee Speed with 3 interchangeable barrels,that could be changed by hand .......strong hands ,for sure,.........takedown rifles nearly always have loose threads ,tightened up by a spacer screw .

[missionary5155]

Good morning
We have a Roller in 45-70 that the barrel was loose. Applied locktight 35 years ago and it is still holding firm.
Mike in Peru

[indian joe]

Good morning
We have a Roller in 45-70 that the barrel was loose. Applied locktight 35 years ago and it is still holding firm.
Mike in Peru

I used red bearing mount on a floppy loose 92 ------ we rebarrelled it 40 years later and had to use an oxy torch to get the old barrel out.

[country gent]

If you have the room and equipment the correct fix I to lightly face the barrel shoulder to time it up. Usually about .003 per hour its off. On military rifle barrels the didn't time they rolled the shoulder down and back to get it timed up. They had converted some pipe cutters to rollers for this to be done in the field. Lock tite may work and hold, I would use red, clean and degrease threads good then apply and let cure got several days.
If you can find the headspace gauge would recommend hand tightening barrel and checking headspace go no go. If a swapped barrel then it may be correct for the existing shoulder on the barrel. Your only talking a couple thousandths here so a shim isn't going to do it. Check headspace with barrel hand tight and witness marks aligned, see what you have there and then work from there. If you have the room on the shoulder then face it back to time or roll the edge to fet what you need

[Rick B]

A good machinist could make a proper dimensioned metal spacer. That could then be locktited into place. Barrel would then have thread tension and index properly. In most cases these spacers are .002-.006” and can hardly be seen if dimensioned properly. This would be the correct way to resolve your issue. It’s common to run into this with older single shots and leverguns. Round barrel leverguns with vise marks will sometimes exhibit peen marks where the barrel mates against the receiver face. They did this to try and stretch the bearing surface to solve the issue of turning past the index mark. This fix rarely lasts. Locktite changed everything!
Rick

[VenisonRX]

After reading the responses and thinking about it and looking at it again I think a shim between the barrel and the receiver might be the best bet. The barrel is only hand right after it has passed the witness mark by a hair and it just starts to run into issues with the extractor. Any more torque and the block won’t close and the extractor doesn’t line up with the slot in the barrel. Not confident enough in loctite alone to keep it timed without it being at least snug to the receiver.

I don’t own a lathe so anything other than applying correct torque with my action wrench and barrel vise will require outside help. Is there a source for anything resembling barrel shins? Eyeballing it I would need less than .006 if my normal source of soda cans around .008 is worthwhile information. I’ve never worked with a machinist shop before and have no idea how to start with that. The .002 might be a place to start. How much torque would I be looking at to be correct?

I’m in the Cabot area of Arkansas if there’s anyone local to that area on here that knows about sharps actions.

Would I be better off putting a new barrel on this thing? The old one is in no way damaged that I can tell other than this timing issue. Thanks again for the advice.

[VenisonRX]

here’s a photo of the witness marks with it hand tight. The action will not close with it like this. Lining up the witness marks does allow it to close properly and headspace.

[john.k]

A shim of 001 or 002 will be like tissue paper,it will simply crinkle as the barrel is tightened on it.......completely impractical,not to mention the extreme difficulty pf making it......to fit a shim,it will need to be something like 005 min,and so the barrel will have to be faced to accomodate it......... a smear of nutlock Loctite will hold forever ,but dont use any accelerator,or the barrel may set not fully into position.....for the same reason ,dont heat anything......The reason I suggest nutlock ,is the barrel may need to be removed ,and the stronger Loctites may cause a disaster..........as an example ,I was asked to remove a boat propshaft from a coupling with a combination of red loctite and rust......took a 60 ton press to break it free.

[turtlezx]

try making a shim from soda cans theres a endless supply tighten up till lines up correctly
some factory barrels are put on with a 3 foot long bar wrench with lots of tork

[Bent Ramrod]

I forget which gunsmithing or machining book it was in, but the author remarked that square threads were not the proper setup for something that was to be screwed together, unscrewed, and screwed back together more than a couple of times. Unlike v-threads, they loosen up quickly, resulting in a rattly, sloppy fit. A previous owner might have done that to your conversion carbine.

That said, I would say that a shim around the barrel shank would be the solution to the problem. Measure the thread pitch (threads per inch) on your barrel shank. (Say, for argument, that it’s 10 TPI, as given in Frank deHaas’ book.) Then gauge how much of a turn past your index mark the barrel will go with a crush fit against the receiver. Say it’s 1/16th of a turn. So the actual slop would be 1/16th of 1/10th of an inch, or 0.00625”. So a piece of 0.007” shim stock ought to get you there.

Brownell’s offers a kit of steel shim stock from 0.0015” to 0.010” thickness, if I recall.

I make “barrel washers” out of shim stock by soldering a piece of the stock onto a the end of a chunk of round stock, and cutting the inner and outer diameters on the lathe. Then I melt the “washer” off the stock, clean it up, put it on the barrel and wronk the action home with a barrel vise and action wrench.

Lacking such equipment, you could draw the inner and outer diameters on the shim stock with dividers and a caliper, cut inside and outside with tinsnips and file any rough spots to fit. It should screw onto the minor barrel diameter up to and against the barrel shoulder.

You could perhaps get by with a pair of hardwood blocks with an appropriate sized hole bored or rasped through them down the centerline, clamped around the barrel and tightened in a heavy bench vise on a solid workbench. Then another piece of wood, with the end cut to fit through the breech mortise on your action, is used as the action wrench to tighten the receiver onto the barrel up to the witness mark.

A certain amount of prudent judgment as to how much strain this makeshift setup will allow you to put on the receiver to tighten it up is necessary. Ham-handedness can spring or distort the receiver. If it’s going too hard to get the index marks to match, then a piece of 0.001” thinner shim stock, done the same way, might be indicated. Or, perhaps, sending the problem to a professional single-shot gunsmith with the proper equipment.

[Deadeye Bly]

Unscrew the barrel, then carefully peen the shoulder on the barrel towards the threads all the way around. A few thousandths will do it. Then assemble with loctite and it will last the rest of your lifetime. If you don't want to peen the barrel then peen the thread closest to the shoulder toward the shoulder. Either will give you some tension on the connection while the loctite cures. I worked in the mechanical repair business for 37 years and we often referred to loctite as "steel glue". It is your best bet.

[M-Tecs]

I forget which gunsmithing or machining book it was in, but the author remarked that square threads were not the proper setup for something that was to be screwed together, unscrewed, and screwed back together more than a couple of times. Unlike v-threads, they loosen up quickly, resulting in a rattly, sloppy fit. A previous owner might have done that to your conversion carbine.

In firearms square threads are normally the shallow type but square threads of normal or shallow (stub) depth do not loosen quickly. Square threads are normally used for high load applications.

https://www.rempco.com/square-thread/

Square Thread
Square threads are primarily used in applications where high power transmission efficiency and high-load capacity are necessary. They are the most efficient thread form owing to thread flanks that are perpendicular to the thread axis. As a result, radial forces on the mating nuts are eliminated and system wear is reduced.
Square threads are useful in cases where side loading is likely to occur, since the perpendicular thread flanks eliminate wedging. In such cases, it is necessary to minimize diametrical clearances between opposing threads or independently support the screw and nut to maintain axial alignment.



Since it is an original I would not roll or peen the barrel. I have done both for M-14 and M1 barrels but the intended use for these was for service rifle competition. Once shoot out they became tomato stakes. Original Sharps barrels have significant collectors value. With the shim nothing is modified.

[DocSavage]

My last job before retiring I was in a tool crib we had sheets of plastic shim stock from .001 to .030 of an inch,perhaps you can order some from McMasters or similar company. Plastic may not be the idea material but a shim/washer would be easier to fabricate. Once you know the correct thickness a metal shim will be a snap to make. We also had derin and teflon stock that was used for making spacers/washers as well.

[dogrunner]

If that was my rifle I'd pull the bbl and roll the rcvr facing edge.........either that or as has been suggested, peen it.......roll should be less noticable if properly done tho.

[varsity07840]

You could send the carbine to Charlie Hahn. He is all things Sharps.

[VenisonRX]

That said, I would say that a shim around the barrel shank would be the solution to the problem. Measure the thread pitch (threads per inch) on your barrel shank. (Say, for argument, that it’s 10 TPI, as given in Frank deHaas’ book.) Then gauge how much of a turn past your index mark the barrel will go with a crush fit against the receiver. Say it’s 1/16th of a turn. So the actual slop would be 1/16th of 1/10th of an inch, or 0.00625”. So a piece of 0.007” shim stock ought to get you there.

Measured the shank and it’s giving me about 10TPI. When you say 1/16th a turn do you literally mean 1/16in of a 1in circumference barrel? My barrel has a 3.911 circumference and the witness mark ends up 1/32 past the index at hand tight. Which works out to be just over 1/128th of a turn if I follow the logic right. So the slop would be 1/128th of 1/10th of an inch or 0.0008. With a slight amount of torque and a little blue loctite that means I could probably get away with 0.001 using this formula?

[VenisonRX]

You could send the carbine to Charlie Hahn. He is all things Sharps.

Think I’ve heard of him. That’s the guy who makes the cardboard tubes and gas checks the percussion blocks right? Is he on this forum to ask questions? I know a lot of those guys are on the Shiloh forum but I’ve never been able to get an administrator to respond to a registration request.

[M-Tecs]

Measured the shank and it’s giving me about 10TPI. When you say 1/16th a turn do you literally mean 1/16in of a 1in circumference barrel? My barrel has a 3.911 circumference and the witness mark ends up 1/32 past the index at hand tight. Which works out to be just over 1/128th of a turn if I follow the logic right. So the slop would be 1/128th of 1/10th of an inch or 0.0008. With a slight amount of torque and a little blue loctite that means I could probably get away with 0.001 using this formula?

Circumference means nothing for this application. A 10 pitch barrel advance .100" per revolution. 1/16 of a rotation is .00625. You will want .001" to .002" additional thickness for compression when you tighten the barrel. You should have a barrel vise and action wrench for this.

Charlie Hahn - etb9601@gmail.com 410-627-4726

[VenisonRX]

Thanks for the correction. How do figure how much of a rotation? I’m seeing 1/32 in past the witness mark. Below is a picture of what I mean. How do I convert that to fractions of a rotation?

I also have a proper barrel vise and action wrench for this.