Breach plug? Need some pro input, pictures

[Mule333]

Hi,

Look at these pic’s please. Tell me what you think. Is this plug seating properly. It’s a Colerain .40 cal.

First pic is “clean”
Second, I dabbed some permatex on the inside shoulder of the barrel then seated the plug.
Last pic, look at the paper towel...

I’m a noob, first build. I’ve watched Bill Raby’s YouTube videos about a thousand times...

I’ve got more pics if needed.

Thanks, Mule

 

[Phil Coffins]

Looks like you have good seat, only thing I would of done is make the plug shorter before starting. Five to six threads are plenty and allows the lock to set further back.

 

[Mule333]

Thanks Phil... but wouldn’t a shorter plug cause problems? A gap between the breach plug and the inside shoulder of the barrel?

 

[Phil Coffins]

The plug and the barrel threads are both shorter to give the same fit to the inside and out like you have now. Modern barrels and plugs are generally made with longer then needed threads. It won’t be a deal breaker but having the shorter breech and the lock back just a bit makes a more refined build.

 

[Larry Akers]

I recommend you use the plug as is. Shortening the plug means you have to remove material from the breech to get the face of the plug to seal again. Getting the plug to bottom in the bore AND mate tight to the outside face of the breech AND time correctly to a barrel flat may be a bit much to ask of a novice. It takes some skill even using a lathe.

 

[Flintandsteel]

Mule,
I’m not sure of the purpose of the Permatex and paper towel. If you want to check for fit up on that plug, clean the breech plug well, paint the contact area with a magic marker, when It’s dry, thread it back in and out. You should have contact all around, shown by scraping away of the marker.
Any reputable barrel maker should have that fitted up nicely. You don’t need to adjust anything till you know for sure. It is NOT necessary to shorten your breech plug. You just need to locate the barrel and lock, so the touch hole clears the front of the plug.
I hope this helps.

 

[user 34300]

Regarding shortening the plug. Some will suggest notching the plug to move the touchhole to the rear. Although it has been done a lot, I, and many others, think this is a bad idea. The seal at the nose of the plug will be ruined. It will be impossible to clean properly.

 

[Kansas Kid]

It appears to have good contact at plug and barrel. Just pay extra attention to allow for proper clearance between flash hole and breech face. Avoid the nasty notch that some cut in the plug face at all cost. If needed have a counter bore or full groove dia radius cut in the plug face to gain clearance. I prefer a flat counter bore so a flat breech scraper still works.

 

[Norman Brooks]

Rice barrels are approx. .500 as compared to others, and they have a perfect fit also. With the longer ones you have to get the tang lower to make the wrist look good, I usually notch the breach plug under the tang and hammer it down and tig weld it in place that way you have a good transition into the wrist. other wise you would have to move the touch hole back into the breach plug area. this is just my opinion...

 

[Mule333]

Thanks Guys for taking the time to reply.

Yes, I’m going to leave it as is. I just was not sure that I was getting good plug to barrel fit. Needed another set of eyes to look at it.

Thanks, Mule333

 

[billraby]

It looks like it is sealing up good. If it is tight against the back of the barrel and the flats are lined up, then you have it finished.

 

[oldwood]

Mule..................I'm with Norman on this one , but shorten the lug on the underside of the plug , differently. Since only about 3/8" of lug is required to put the wench on the plug to tighten it , try this........With the plug finish installed into the barrel , Draw a 1 mm felt tip marker line extended from the bottom surface of the breech plug tang to w/in 3/8 " of the rear surface of the barrel breech. Next , extend the line to the bottom side pf the new breech plug. If you turn the barrel upside down , the felt tip marker line should be in an " L" shaped configuration. Hack saw away the metal from the rear underside of the plug following the "L" marker line. Clean up the sawed surfaces with files. HERE's the secret to bending a tang to fit the stock contour . Using a bench vise......open the vise jaws slightly more open than the thickness of the plug tang to allow for movement of the tang between the vise jaws. ( To prevent scaring of the visible top surface of the tang , a piece of brass could be inserted between the top of the tang and the vise jaw. ) To bend the tang to fit the inlet as you apply the inlet , put the end of the tang LOOSELY between the vise jaws to allow for movement , with bottom of the barrel towards you, , barrel vertical, and gently pull the barrel towards you a little at a time . Inlet a little , bend the tang a little , until the tang is completely inlet as desired. Avoid bending the tang back and forth , or breakage will occur. Using this method , I've adjusted close to 150 plug tangs with only 2 broken ones. ............Tig welding is above my pay grade , and admittedly i'm not smart enough to do it. Hope this helps................oldwood

 

[Mule333]

Thanks again, can’t thank you guys enough for your input.

Don’t know what us noobs would do if it weren’t for you guys and your leadership.

I’ve been reading 2 books that Mike Bellevue suggested. Gunsmiths of Grenville county and The Art of Building a Pennsylvania Longrifle. Or I should say... I’ve been studying them. And everything I read says to make absolutely sure you have a tight fit from breach to barrel.

As for the back of breach... at the tang... I am going to follow Norman and Oldwoods advice on bending the tang. In fact it’s already in an “L” shape configuration. It that’s down the road a little... I’m still trying to teach myself to inlet a swamped barrel. Using a 2x4 to practice on.

Thanks, mule