Custom breech plug

[Needstuff03]

I need a breech plug for a hopkins allen underhammer, it would have to be a one off or custom job needs to be 3/4×16 for the threaded part and then go to 5/8ths cylinder to fit in the action. Could I buy a 3/4 plug and cut off the tang and weld a 5/8th lug onto it? Any help or direction would be appreciated.

 

[bubba.50]

Maybe buy a 3/4 by 16 bolt & turn down in a lathe to make the 5/8ths lug?

 

[1BadDart]

Do you have a friend with a lathe?

 

[waarp8nt]

You would be better off with a 3/4x16 bolt or all thread, keeping the threads you need and turn it down to 5/8 on a lathe.

 

[Needstuff03]

I dont have access to a lathe, and what grade bolt would it take.

 

[SDSmlf]

If I were to use a bolt, I would probably pick a non-plated Grade 5, though any grade would work. What I don’t like about bolts is that the threads are rolled, not cut, and at least to me vary some. My reason for picking Grade 5, is they (and Grade 8) always seem to have more consistent threads than ungraded/Grade 2 bolts.

I would make friends with someone that works in a machine shop and/or has access to lathe. You are looking a a very simple task on a lathe.

Hope you find a workable solution to your challenge.

 

[Needstuff03]

Thank you all for pointing me in the right direction

 

[deerstalkert]

a poor mans lathe could work for you. get your bolt, center drill and tap the tang end for a 3/16 bolt. cut the head off the 3/16 bolt and chuck it into a drill press (if you have a drill press) . turn the tang area down with a good sharp ******* file. if you don't have a drill press, disregard.

 

[SDSmlf]

a poor mans lathe could work for you. get your bolt, center drill and tap the tang end for a 3/16 bolt. cut the head off the 3/16 bolt and chuck it into a drill press (if you have a drill press) . turn the tang area down with a good sharp ******* file. if you don't have a drill press, disregard.

Might find oneself lacking material trying to get a 3/4”-16 thread from a 3/16” bolt, even with a real fancy drill press.

 

[SamTex1949]

you might try writing and asking if they may have a source for what your looking for . Wouldnt hurt to try or even Dixie Gunworks.
https://www.gunpartscorp.com/gun-manufacturer/hopkins-allen/muzzleloading-rifles

 

[flynfred]

pecatonica has them in stock, otherwise 3/4x16 bolt cut to size

 

[Needstuff03]

I just shot them an email

 

[deerstalkert]

Might find oneself lacking material trying to get a 3/4”-16 thread from a 3/16” bolt, even with a real fancy drill press.

the 3/16th bolt is just for chucking into the drill press jaws. most presses won't take a 3/4. think about it.

 

[SDSmlf]

the 3/16th bolt is just for chucking into the drill press jaws. most presses won't take a 3/4. think about it.

Got it. Was not considering using the 3/16” bolt as a holding piece for the drill press chuck, although, the larger drill presses where I worked have at least 1” max capacity. Believe it would take some effort even with sharp file to work down a 3/4” diameter driving it with 3/16” diameter bolt without bending or braking the bolt. Doesn’t mean it can’t be done. I would just use a lathe, however, if one doesn’t have a lathe, one has to improvise.