breech plug question

[tat]

I have asked this before last year but I could not find it in a search.

I have a .50cal blank that I am putting a breech plug of my own design in. What diameter hole/thread should I use in this barrel for the plug.

How deep should the plug go into the barrel?

Thanks

 

[dlemaster]

I'd use 5/8"-18 thread.
Hope this helps.

Regards, Dave

 

[tat]

Thanks

how deep should I go?

 

[dlemaster]

I'd go 1/2" deep. 1/2" is plenty strong for a BP rifle. If you go deeper you have to either notch the face of the breech plug or move the lock too far forward to get good stock architecture. Be sure and use a bottom tap to cut the last few threads up close and tight againt the bore of the barrel. Then make sure the plug screws up tight against the shoulder at the same time it comes up tight against the barrel flat. You don't want any gap where powder fouling can accumulate and cause corrosion. If you notch the breech plug it's hard to keep the area clean, although a lot of original guns have notched faces.
Hope this helps.

Regards, Dave

 

[tat]

thanks

I am having trouble locating a 5/8-18 locally, would a 5/8-11 (at the hardware store) be safe or is 11 threads out of the question?


Thanks again

 

[dlemaster]

The fine threads are better. They have a much greater bearing surface. If your having a hard time locating a tap locally, I would go online and find one. Brownells I'm sure carries them but they will likely be slightly higher in price since they are a gunsmith supplier.[url] www.brownells.com[/url]

Look for anyone supplying the machinest trade both locally and online. It is a fairly common tap.

Regards, Dave

P.S. I just checked quickly at Brownells and can't find them. I got my last set from a local Sears Hardware Store.

 

[tat]

Dave,

I will find an 18 thread somewhere.

My 5/8" stock(for the breechplug) will be mild steel (possibly 1018). Do I need to use kasenit on it after I drill the flash hole and thread it? or can I leave it as is.

Thanks again

Tommy

 

[Henry]

Following my gouru 's word of wisdom :
( Kit Ravenshear , books available at all
gun parts outfit , Dixie , Track etc )
I would use a coarse thread , but anyway you will have to hunt for a bottoming tap in either case .

 

[TANSTAAFL]

Following my gouru 's word of wisdom :
( Kit Ravenshear , books available at all
gun parts outfit , Dixie , Track etc )
I would use a coarse thread , but anyway you will have to hunt for a bottoming tap in either case .

Or, run in the starter tap, and regrind (keep it cool) into a bottom tap, can always revert it back to a starter tap. Just because I have some rather short taps, don't ask me how I know. :grin:

 

[davy]

Just because I have some rather short taps, don't ask me how I know. :grin:

Thats what SHE said! :hmm: :shocked2: :redface: :rotf:

Davy

 

[Henry]

Hey ..... That IS smart !
How come I never thought of it alone :cursing:

Buying over the counter , at retail price
not only I had to run all over town to find
a bottom tap but the price was four time the price
of the standard one ( talk about marketing stratégy)

 

[johnathon]

Hey google victor machine tools they have any possible tap or die for that matter , best prices hands down

 

[Old Ironsights]

http://www.victornet.com/cgi-bin/victor/index.html

Absolutely.

$13.90 for a 5/8-16 or 5/8-20

 

[tat]

The material I am using for the breechplug is 5/8" bar 1018. Do I need to use Kasenit on this after I drill it and thread it? Or can it be left as is?

Thanks

 

[Old Ironsights]

The material I am using for the breechplug is 5/8" bar 1018. Do I need to use Kasenit on this after I drill it and thread it? Or can it be left as is?

Thanks

Couldn't tell you. I just know where the tools can be bought.

 

[renovato]

Kasenit only surface hardens to prevent wear from friction. It's not going to add strength to the plug and might make the threads brittle. I'd leave it as is.

 

[tat]

Thanks Plink! :thumbsup: