Author Topic: Breech plug face, Flash hole & Pan relativity  (Read 510 times)

Offline DanL

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Breech plug face, Flash hole & Pan relativity
« on: May 31, 2023, 05:39:53 PM »
Good morning All. I started this thread as to not divert the recent discussions about pan and flash hole location but to solicit your opinions on the subject.

Back when I first decided to attempt to recreate a flintlock longrifle, I asked everyone questions related to this triangle of important proximity. I went to Dixon's Fair for several years and bothered all the greybeards. I decided to purchase a breeched barrel from Don Getz, a lock from Mr. Chambers, some brass from Reeves Goehring & wood from Dunlap woodcrafts. From the Gurus,  I picked up all the makings of a longrifle reflecting the later half of the 18th century.

Disclaimer: I am not saying that the choice I made is the best way or a wrong way. It is what I chose for the following reasons.

After much discussion with the Gurus about positioning the breech plug face, flash hole and pan, I settled on Mr. Getz's and a couple of others' suggestions of where I was to locate the three features. The flash hole was centered on the barrel flat where the breech plug fits to the bore. In other words at the very bottom of the bore.  A notch  was filed in the breech plug face. The white lightning flash hole liner was installed centered with hole pointing to the face of the breech plug. 

Mr. Getz explained, that right or wrong, many of original barrel's flash holes were positioned w/notch in the breech plug face. It allowed better positioning of the lock further back relative to the barrel. Also, each time it was fired, the pressure escaping through the vent will self clean any burned blackpowder crud from the breech face. Mr. Getz cautioned that this method of flash hole placement may " if not properly maintained" allow corrosive powder residue to make its way into the breech plug threads and cause rust/corrosion which may render the barrel unsafe. He suggested that modern builders prefer to place the lock & flash hole more forward of the breech plug and its face to prevent filing a cone in the breech plug face.

I built my rifle with a filed cone in the face of the breech plug allowing the lock to be positioned slightly more rearward and take advantage of a self cleaning crud removal each shot. I installed the breech plug with a quality copper based anti-seize compound. Every 5-7 years or so, I remove the breech plug to inspect the situation. After 20 years, with proper maintenance, I have had no issues with corrosion in this area. Also, I have not had any issues with crud build-up on the breech plug face.

Each person has to decide how their longrifles are built. I will admit that there is a possibility that one day I will find corrosion in the breech plug area (Threads in particular). I do not plan to ever sell this particular rifle. All other flintlock muzzleloaders that I have purchased or assembled, have the flash hole forward of the breech plug face with no notch filed in the face. Each one of them leave some powder residue build-up on the breech plug face after firing. I have observed several early barrels and they all had a notch filed in the breech face.

Respectfully,
Dan
 
« Last Edit: May 31, 2023, 06:51:52 PM by DanL »
From God's Farm in Alabama; God bless America & "Alba gu Brath !!"

Offline A.Merrill

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Re: Breech plug face, Flash hole & Pan relativity
« Reply #1 on: May 31, 2023, 09:20:02 PM »
 If you need to notch the plug do it. Guns today if built right should have the threads in the breech greased. Most people use the anti seize grease and it may stop corrosion penetrating the threads in the breech. High temperature wheel bearing grease is far better, it will stop corrosion and the flash of heat from the powder will not last long enough to melt the grease. So burnt powder and corrosion can not get into threads. I worked for a oil company for 20 years I did everything there was to do there including working in the lab testing lubricants.   Al
Alan K. Merrill

Offline Martin S.

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Re: Breech plug face, Flash hole & Pan relativity
« Reply #2 on: June 01, 2023, 03:28:36 AM »
Where does one buy "high temperature wheel bearing grease"?

Is there a specific brand you recommend?

Offline A.Merrill

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Re: Breech plug face, Flash hole & Pan relativity
« Reply #3 on: June 01, 2023, 05:28:03 AM »
 All auto parts stores has it, even Walmart in the auto department. It comes in a 1lb. tube or 1lb. can. Actually all wheel bearing grease is a high temperature grease.    Al
Alan K. Merrill