Sharps Gas Seals

[Jim Wimbish, 10395]

The post by the owner of an original Sharps intrigued me. I have never considered shooting either my slant breech or my Model 1863, but I do occasionally shoot a modified Pedersoli with the o-ring mod. What gets me is how they could get a gas seal to function with all of the fouling produced by black powder. The modified Conant design was eventually used in artillery but the fouling issue persisted until the invention of smokeless powder. Eventually the artillery went the way of the 50/70 Sharps and went to a metallic cartridge. I have two repro Sharps that use the later cartridge design in a 45/70 cartridge and they work beautifully. One is a Sharps carbine which Perdersoli made in 45/70 instead of 50/70 so that it could be shot with smokeless powder in a readily available caliber.

I have taken an original Sharps breech block apart for a good cleaning and it was quite a job to get the gas seal plate off the block. It took a teeny screwdriver and a lot of careful prying to eventually get it out. I don't see soldiers in the field going through this process to keep this floating plate from freezing up. The way that the system is supposed to work is for gas to come back in the chamber and the pressure on the angled interior of the face plate would push the plate forward, sealing the breech against the sleeve in the barrel which was fixed in place by an armorer within a certain tolerance. Given that artillery had enough of a problem with black powder to eventually go to brass shells, I have a hard time believing that carbines and rifles with much smaller bores could be kept clean enough for these systems to function properly.

If this plate could actually float using pressure built up in the chamber, with only rudimentary field cleaning with soap and hot water, then this is truly an amazing design. Did the plate really float and seal the breech or was it pretty much just set in place?

[Hal]

My wife shoots an original 1859. I cannot get the plate off the front of the breech block. I've never had it off. This thing seals up just fine. We clean it by soaking in hot soapy water and then WD-40 to displace any residual moisture then oil to keep from rusting. Maybe we are just lucky, but it has never leaked gas.

[Steve Weems]

There is a YouTube video of a guy shooting an original slant breech Sharps- the flash and smoke escaping from the breech would do a 4th of July celebration justice. After watching that I realized why Sharps went to the 1859 design.

[geezmo]

Hal,

Your cleaning procedure is the same as the Sharps company intended for the common soldier or other user of their rifles and carbines.

If you look at the 1859 and 1864 Sharps manual/catalogs all they say about cleaning is "To CLEAN THE ARM, relieve the lever key from pressure, by throwing down the lever guard, and then take out the key, which is replaced with the guard in the same position. Remove the slide and dissolve the hard substance with water if any has collected in its cavity, taking care not to use any metallic tool in the operation, by which the slide, or gas-ring, might be injured. The bore is easily washed, or cleaned with a wet brush, after which, wipe it quite dry, and oil it, and the slide, with sperm oil, tallow or other pure oil, free from salt and acids." That's it.

Apparently any more involved procedures and parts removal were reserved for unit armorers or civilian gunsmiths. We all want to tinker more than some among us should. Fortunately we have work benches and a bunch of tools at our disposal that the common soldier of the period did not.

Barry Selzner

[Peter]

Well I'm in your camp Hal. There is no way the gas leakage issue would prevent me from trying the thing out. Just to be sure, first shots off the bench with left hand and arm clear. That's part of the reason I stay with mild loads -- very little risk of calamity. Sorry to all you safety Sallys out there.


I placed that post about firing my Sharps NM1859. My reason for wanting to do this is simply to know that is fully functional and also to get a feel for what it was really like for those men who gave so much. I plan to put it back on the wall after firing a few rounds at the finals and maybe a few more with my sons and grandsons at home.

I have gotten lots of advice about the floating breech-block plate seizing up. Indeed mine was totally frozen on and many attempts to carefully pry it up had failed. Whoever fired that thing last did not clean it, and I have had it on the wall for 20 years but it has been well oiled and I doubt that any further corrosion occurred on my watch.The nipple was completely clogged. Ditto for the cleanout port and nozzle. I had to give it lots of deep cleaning in boiling soapy water and then hand reamed all the openings using fine drill-bits. All the channels were impassable, but it finally gave way and cleared. The plate was still stubborn and I soaked the block in penetrating oil for a week, alternating between the oil and an acetone solvent bath. Finally, clamping the plate in a vise and tapping the main block and rocking back and forth by hand broke it free. The corrosion joining the two parts did not cause severe pitting, and the mating surfaces cleaned up nicely with a jewelers file and carborundum stone. These mating parts are close to perfect after cleaning. I have little doubt that the plate will do its intended job.

A couple of people have weighed in about the sleeve in the barrel, some saying that it is supposed to float back and forth, and the gas pressure forces it against the breech-block plate. Others have said that it was an interference fit done at the factory and was not meant to move during firing. Scholarly books on the Sharps by Frank Sellers, John McAulay, W.O.Smith and Richard Hopkins do not mention anything about this sliding bushing in the barrel, so I tend to believe that if this were to have been the desired design concept, at least one of them would have mentioned it. Consequently, it would seem that the floating plate was the only part which moved in an attempt to decrease gas leakage. It does not surprise me that the breech-block pate gets fouled easily. These are very close tolerances and any dirt or aggregate getting between those surfaces is bound to lock the parts up. Looks like that was just an inherent weakness in the design. Thanks Very Much for providing guidance to me! Peter Chandler

[Maillemaker]

I got a Pedersoli 1859 Sharps a couple of years ago. It has an "attempt" at the Sam Dobbins o-ring modification, but it did not work well on my Sharps. You could get off about 10 shots before the breech block would become immovable. In addition, when it was time to clean, you could tell there was loads of gas leaking up under the forestock as it was sooty under it.

I had Larry Flees do his job on it. You can see my review here:

https://www.n-ssa.net/vbforum/showthread.php/13515-Review-Larry-Flees-Pedersoli-Sharps-Carbine-rework?highlight=larry+flees+review

Steve

[Jim Wimbish, 10395]

I started this thread and I think that we can pretty well wrap it up now. I had a chance to speak with Charlie Hahn over the weekend about the model 1859 Sharps with the improved Conant gas seal. While the sleeve in the barrel could be moved, it was not supposed to move during operation. It was typically tapped back to where it had a close fit with the face plate of the breech block. So while the sleeve could be moved by an armorer, it did not move under the normal operation of the gun. As for the floating face plate. I told Charlie that this sounded like some sort of fairy magic and he agreed. The plate really didn't move and cetainly didn't help seal the breech. Soldiers were told to carry plenty of water with them and use it to soften up the hard fouling on the breech block so that the breech could be opened and closed. The onus was on the soldier, to make sure he knew when and how much water to use to keep his gun fuctioning. The problem of breech fouling in the Sharps was only solved when they went to the 50/70 brass cartridge.

[mgmradio]

Attached is the original patent for the Conant breach. This should clear up how it works.
On my New model Sharps, the Conant plate is free, though it is a press fit. The bushing in the barrel was damaged when I got it and I had a friend remove and replace it. When firing the gun with 55gr of ffg the Conant plate moves forward from the fully seated position and seals the breach nearly completely. After firing the plate is a couple of thousandths from being flush with the block.

[Peter]

Attached is the original patent for the Conant breach. This should clear up how it works.
On my New model Sharps, the Conant plate is free, though it is a press fit. The bushing in the barrel was damaged when I got it and I had a friend remove and replace it. When firing the gun with 55gr of ffg the Conant plate moves forward from the fully seated position and seals the breach nearly completely. After firing the plate is a couple of thousandths from being flush with the block.


That's a nice piece of information. It's obvious that if the so called floating breech sleeve were really a part of the quest by Sharps to reduce gas leakage, it would have been clearly mentioned in the patent application, so I guess the lack thereof refutes the floating sleeve concept. While that has been employed in some reproductions, it surely was not part of the originals. Peter Chandler

[geezmo]

Peter,

See my post, from 1/2/16, below for an explanation of the bushing, bouching or chamber sleeve.



"There seems to be an obsession with modern day Sharps shooters to remove and clean this bushing, or "bouching" per the Sharps literature, every time they shoot and clean their rifle or carbine. Reread the previous posts by Spadegrip and Harley1247. The bushings were not meant to move or be removed in normal use, at least not the original guns and not by the common soldier. I don't know about the recent Italian imports. I know Pedersoli makes and sells a special tool for the purpose. Maybe their design is slightly different. I only know one person who removed a bushing from an original and it was a bear of a job. He also had to take the barrel out of the receiver as the bushing was too long to clear the opening for the breech block. So, removal was not a part of routine cleaning.

If you look at the 1859 and 1864 Sharps manual/catalog all it says about cleaning is "To CLEAN THE ARM, relieve the lever key from pressure, by throwing down the lever guard, and then take out the key, which is replaced with the guard in the same position. Remove the slide and dissolve the hard substance with water if any has collected in its cavity, taking care not to use any metallic tool in the operation, by which the slide, or gas-ring, might be injured. The bore is easily washed, or cleaned with a wet brush, after which, wipe it quite dry, and oil it, and the slide, with sperm oil, tallow or other pure oil, free from salt and acids." The only parts intended to routinely move or be removed were the breechblock or "slide" and the Conant gas check or "gas-ring".

For an explanation of the bushing, refer to Frank Selller's book "Sharps Firearms". On page 343 in the chapter on tools he says "Another of the unknown tools during the early percussion period of the Sharps rifles is the "bouching clamp and rod." This tool was used for adjusting the head space of the guns. It was inserted into the front of the chamber and engaged the front end of the bouching. The breechblock was closed after the insertion of the bouching clamp. The bouching rod was inserted through the muzzle and held the bouching clamp tight against the walls of the chamber while the bouching rod was tapped, forcing the bouching back tight against the face of the breechblock." This was apparently only done as an adjustment as parts wore and must have been done by armorers with the skills and tools and only as needed.

If you have a repro and are having problems with cleaning, gas leaks and action locking up, I would consult Charlie Hahn and have him do one of his breech jobs. If you have an original and are having gas leaks, see if Charlie could make this "bouching" adjustment, otherwise, I would leave it alone and find another shooter."

Barry S.