interesting, hawken breech plug

[Joe S.]

started my build and did enough reading here and elsewhere and have a question. From what I could gather there is a flaw in the design of the breech plug.Powder chamber is to small and flat across the top.If powder bridges across the flat you run the risk of inconsistent fire.Figure I'd pull the breech plug and take a look for myself and check it for fit while I got it apart.Fit was perfect and the powder chamber was 3/8" wide.While I have it apart I will drill it out  a hair and cone and polish it.My question,do you really think 3/8's was all that small?From what I read here these plugs had smaller powder chambers?

[Herb]

Track's Hawken Flint Hooked Breech & Tang #Plug-FH-16-3 has a powder chamber that measures .285".  My Flint Hooked Breech for 1" plug,  #Plug-LRF-16-3, which I think you have, measured .360.  I would get about 30 flashes in the pan in 50 shots with this, with a .58 flint Hawken I built.  It practically would not set Swiss 1 1/2F off.  I drilled mine out to about .440.  Track says of their Hawken pistol flint hooked breech "Drilled for a powder chamber, you may enlarge this cavity, but it must remain smaller than the bore diameter, to prevent entry of a cleaning jag and patch, which might become stuck."  Of course, if it was bore diameter, there would be no problem.....  If you feel adventuresome, just build it as is and find out for yourself.

[Turtle]

 A friend of mine has  a pedrosoli Mortimer rifle. It's pre-chamber was so small  you needed a .22rf jag to clean it. He had ign. problems and had it opened up a lot and solved them. It was supposed to be an exact replica of the original, what are we missing? It evidently worked for them.
                                               Turtle

[Don Stith]

THe people that make the breeches don't know what caliber barrel you will fit it to. It would be an inventory nightmare to carry caliber specific breeches, so they make them  small enough to fit the smallest likely caliber. What you do with them is up to you

[Bob Roller]

A friend of mine has  a pedrosoli Mortimer rifle. It's pre-chamber was so small  you needed a .22rf jag to clean it. He had ign. problems and had it opened up a lot and solved them. It was supposed to be an exact replica of the original, what are we missing? It evidently worked for them.
                                               Turtle

 This is an often mentioned problem. It's an attempt to copy an old English Nock breech that itself was brought about to help problems with variable quality powders in use in the 18th century.The theory was that a streak of flame from the chambered breech thru the center of the barrel charge would produced an enhanced performance. Maybe it did back then but today's black powders are of much better quality and no need really exists for it today. I have seen postings on other forums about this problem and redrilling the breech is the cure.
The one reason I can see to make such a breech today is to put the touch hole behind the breech plug threads and make the lock easier to locate.I did it on my 58 caliber flintlock rifle and on the 50 caliber I have in the works now.I used a .358 drill and made a touch hole liner from beryllium copper and it worked fine in the 58
caliber rifle.


Bob Roller

[Scota4570]

I dislike "patent breech" plugs.  I think the advantages are imaginary.  The price of them is unreliable ignition.  IMHO if a gun is not reliable nothing else matters. 

I made a "hawkin"  flint hooked breech plug a while back. The barrel was 1" across the flats.   The threads were 3/4" the bore was 0.54.  I hogged out the chamber to 0.5" ID diameter.  The thread relief cut was 0.667" OD.  That gave a wall thickness of only 0.083" at the thread relief cut.  After seeing what I had done I made a new breech plug!  I keep the old plug around as a reminder to think ahead. 

If you are going to hog out a plug be sure it is safe when you are done. 

[Herb]

Here is my .58 flint Hawken with a smoked dowel that shows the size of the powder chamber after drilling it larger.

[galamb]

I am not a prolific builder by any means, but do build exclusively with patent breeches.

I drill every one of the chambers to the next caliber "below" the barrel (so 45 for a 50 cal barrel etc).

I can't always get real black so sometimes shoot Pyrodex and have never had any bridging issues so don't know if I'm "pre-curing" a problem that wouldn't have existed or not - but figure it's certainly not hurting anything.

[Acer Saccharum]

I spent a lot of time building a breech as shown, thinking it would give me faster ignition. Turned out OK.

But I also use flat faced plugs that seem to be just as fast to me. They clean much easier.

But this design is more of a pain to clean at the end of the day. Shot all day without needing to clean. You need a rod tip that gets down in the recess.

[bob in the woods]

I suppose that like many things, there are those who like them and those who don't. I'm not a fan , myself.  Frankly, I hate them, and don't/ won't have a rifle with one. Any American long rifle of the 18th C that I know of  used a simple flat faced or at most a slightly concave breach face. Easy to clean. No two sizes of cleaning jags or worms required.  More of a percussion gun thing anyway.

[rich pierce]

Patent beeches were all the rage in the late flint period, and without any way of actually measuring lock time, there was the commonly held belief that they fired faster.  There was hot competition between top London makers and everybody wanted a patent. It meant sales.  I cannot understand a reason why a patent breech would be faster. Thicker wall.  Farther for flash to travel.  Ummm.....?

On a percussion rifle, they make perfect sense because the drum method is just not very strong.

[Joe S.]

drilled it out to 7/16 ths.then put a nice radius on it and polished it.Being 58 caliber should be plenty of meat left.

[Turtle]

 I have removed 2 jags/ramrod tips stuck in there!
                                          Turtle

[moleeyes36]

I suppose that like many things, there are those who like them and those who don't. I'm not a fan , myself.  Frankly, I hate them, and don't/ won't have a rifle with one. Any American long rifle of the 18th C that I know of  used a simple flat faced or at most a slightly concave breach face. Easy to clean. No two sizes of cleaning jags or worms required.  More of a percussion gun thing anyway.

Bob,

My feelings exactly, but some people love them.  To each his own I guess.

Mole Eyes

[Joe S.]

I would think a well contoured cone would help from getting jags,ram rod tips from getting stuck.I would rather roll those dice than the flash in the pan dice.What's the other option for a hawken build,drill out to bore size?should have left it alone with the flat?I'm open for suggestions. My first build and am learning as I go.

[whitebear]

Some swear by them and others swear at them.

[Herb]

You have cured a real problem.   With an .070 flash hole you will have no more flashes in the pan than with any other flintlock.  I fired my .58 flintlock many hundreds of times after I opened up the powder chamber, with Goex 3F, 2F and Swiss 3F, 2F and 1 1/2F and had no flashes in the pan that I remember.  You were wise to enlarge that powder chamber, but you would have got smarter (by personal experience)  if you had not.