Modifying 1873 Bayonet to fit .58 Caliber Musket

[wajohnson12]

Greetings!

I’ve been given an original bayonet, and judging by the bluing, I’m assuming it’s an Indian Wars era bayonet. While I’m certainly no expert on the models, I’m guessing it is a model 1873. It is “relatively” close to the correct dimensions of an 1855 bayonet with the internal dimension of the socket being ~0.75”.

Has anyone ever attempted to convert a model 1873 bayonet to fit a .58 caliber musket? I know it will “ruin” it’s resale value and I’m well aware of the modify it vs. leave it alone arguments so let’s not take this thread there. I’m simply wondering if it’s doable and if so, has anyone done it before.

Thank you in advance for any help!

[Curt Schmidt]

Re: Modifying 1873 Bayonet to fit .58 Caliber Musket

Hallo!

The muzzle diameter of an original M1861 Springfield is a nominal .783." Italian repro's can run slightly larger.

"Trapdoor" bayonets are essentially M1855 Type II bayonets that initially had their sockets cold pressed "shrunk" to fit the .45 rifle barrel.

Yes, a M1873 bayonet can be judiciously sanded/ground larger (it is hard to remove much metal and still have an equal inner diameter socket).
BUT, if you do the math, enlarging the inner diameter would leave a thinner "wall" to the socket.. worse yet on "oversized' repro Italian examples.

Others' mileage may vary...

Curt

- - - Updated - - -

Hallo!

Due to a never ending house remodeling, all of my reference books are boxed and stored otherwise I would give you a series of multiple measurements.

:(

Curt

[Calum]

Re: Modifying 1873 Bayonet to fit .58 Caliber Musket

It's definitely do-able. It's what's currently residing on my AS Springfield.

I used the same process that I've used to modify aftermarket bayonets to fit. Clamp the blade (close to the socket) in a vice, with thick leather between the blade and vice jaws.I then use a dremmel to ream out the barrel of the socket. I used to be able to find the perfect grinding heads to do the job, but I haven't been able to find them in a number of years. They were flat, about 1/4" thick and just about the perfect diameter. Last couple, I've been trying different attachments. Still haven't found one that is as perfect, but you end up going through a fair amount of them.

If you really want fun, modify it for a Sharps rifle. Because the barrel actually has a larger outside diameter than a Springfield. And you have to modify the sight channel in the bayonet as well.

But the weight difference, compared to a repro, as well as not worrying about bending it. It's definitely worth the project.

Oh! the look on my wife's face when she realized that I was using a dremmel on an original! It was fantastic! :)

Good luck!
Calum

[wajohnson12]

Re: Modifying 1873 Bayonet to fit .58 Caliber Musket

Thank you both for responding! As always, I truly appreciate the insight from the members of the forum!

[coxto]

Re: Modifying 1873 Bayonet to fit .58 Caliber Musket

Has anyone attempted any modification of the 1873 Trapdoor bayonet and have been successful? Trying to identify bayonet by markings and a person's word has been exhausting when looking online. I would not mind taking a chance on one if so.

[Curt Schmidt]

Re: Modifying 1873 Bayonet to fit .58 Caliber Musket

Hallo!

No, I have not.

But I had a simple test for the M1873 versus M1855 bayonet sockets. And that was just to stick my index finger into it as a gauge of sorts. Of course, the size of my finger will not work for anyone else so each lad has to do it for himself.

More universally though...

The M1855 socket inside diameter measures (at the front) 25/32 and outside diameter 29/32.

The M1873 socket inside diameter measures (at the front) 23/32 and outside diameter 28/32 (7/8).

Curt

[coxto]

Re: Modifying 1873 Bayonet to fit .58 Caliber Musket

Curt- Thanks for sharing the socket dimensions. I did some more reading of re-enlarging the socket and I have decided not to. From what I read, the Trapdoor bayonets are actually M1855. The US had a surplus of M1855 bayonets, there was no need to manufacture new bayonets the Trapdoor. The sockets where cold shaped to the smaller size to fit the Trapdoor. I did not want to risk destroying a bayonet in attempting to make the socket larger without the proper tools. The metal has also been shaped twice and thought that a third time may be the breaking point. I did win an ebay auction on a nice imported Birmingham Small Arms Trade Enfield bayonet for less than what the Trapdoor bayonets are going for. I should have it in a few days.

[wajohnson12]

Re: Modifying 1873 Bayonet to fit .58 Caliber Musket

For the record, I did modify the bayonet and it worked fine. Took a lot of work, but the venture was successful.

Other's mileage may vary.