TC Seneca Breech plug unsafe?

[Scota4570]

I agreed to put a new barrel on a 45 cal Seneca for a new friend.  The barrel was put away uncleaned with a jag stuck near the breech.  The bore is very rough.

My plan was to get a blank 13/16 barrel, use his plug and install a new rib and sights....easy peazie : )

The factory plug in the factory barrel is 11/16" x 20 TPI a .....bastard thread.  TC did use these on 15/16" and 1" barrels.  On this 13/16" barrel the factory plug leaves a wall thickness of only 0.060".  I feel that is unsafe.  Was this a manufacturing error?

Re thread the factory plug?  The powder chamber holes is 0.362" If I go to 5/8x18 the existing threads won't clean up.  9/16x18 leaves a wall thickness in the plug of 0.064"  Too thin IMHO...unsafe?

Buy a new plug with correct threads?  Track has none to sell.  Anyone else sell them?  The plug has some complicated cast contours I can not reproduce.

This one is a real can of worms. I am tempted to lap the snot out of it and put it back together.  Is it safe as manufactured? 

Any ideas on how to proceed?

[little joe]

Try Stonewall Creek Outfitters

[Scota4570]

Upon further examination the 5/8 x 18tpi will work.  Still....what was TC thinking?

[Dphariss]

Upon further examination the 5/8 x 18tpi will work.  Still....what was TC thinking?

Dollar signs.  The tales I could tell. They used to put plugs in the "Hawken" by machine and stretched the rebate on threaded shank to the point that attempts to remove the breech would leave the threaded portion broken off in the barrel . Or so I was told back in the day. The breech is probably too corroded to be used anyway if the bore is really bad.

Dan

[Hungry Horse]

You might have better luck finding a small T/C plug from the patriot pistol. They sold a bunch of them,and towards the end of their run they started producing their own stocks instead of buying them from CaliCo hardwoods. The stocks they produced nearly all failed at the wrist, causing them to stop production. The Cherokee plug would work too, but they were almost as popular as the Seneca, and could be hard to locate also. You might try EBay.

  Hungry Horse

[oldtravler61]

  Scotta take H.H. advice about EBay. You can probably get the barrel an breach plug . They show up quite frequently. Oldtravler

[Daryl]

Track has plugs. I used one of theirs on my wife's Seneca when I rebarreled the rifle to .45 cal. using a GM barrel. Seems fine to me.

[JCKelly]

Caution -
The following is regarded Politically Incorrect amongst muzzle loader shooters.

Consider reading December, 1985 Muzzle Blasts, page 27. The information came to the author from the late John Baird. Mr. Baird had been involved with the lawsuit regarding this xxxmassproduced rifle. The shooter had marked the ramrod to be certain the ball was seated on the powder, with his 60 grain load. Had fired the rifle a couple hundred times. Entire patent breech and threaded portion of barrel separated, striking the shooter in the head . . . notch at the root of the thread concentrated stresses to about 1-1/2 times normal level, in the thin barrel wall.  Lost his left eye, had brain damage, with impaired hearing and balance. This was a .45 caliber rifle, barrel 13/16" across flats with 11/16" breech threads. Steel cold drawn 1117 (free machining).

[jerrywh]

 Don't let yourself get suckered into these deals.  That gun isn't going to shoot well anyway. Tell him the truth and give it back to him.  Neither one of you have anything to gain.

[Scota4570]

Are old muzzle blasts article available on line?  PDF's someplace?  I see the on-line magazine only goes back to 1996.  Before I tell someone I just met that their rifle is a POS,  and unsafe as made, I'd like to back that up. 

He got it for free.  He is not squeamish about spending money on it. A new plug/ tang, and new barrel will take care of the issue.  A franken-rifle is what we talked about. 

I will not put the plug back in this barrel.  I don't think it is safe to fire.  I find is strange that TC is so highly regarded.  IT is a small step up from CVA, but only a small one....IMHO. 

[JCKelly]

Scota4570 you can find my email on this site. I can send you a PDF of all three parts, 1985. 

[Scota4570]

Scota4570 you can find my email on this site. I can send you a PDF of all three parts, 1985.

PM sent.

Thanks,

Scot

[Dave Patterson]

Caution -
The following is regarded Politically Incorrect amongst muzzle loader shooters.

Consider reading December, 1985 ... Entire patent breech and threaded portion of barrel separated, striking the shooter in the head . . . notch at the root of the thread concentrated stresses to about 1-1/2 times normal level, in the thin barrel wall.  Lost his left eye, had brain damage, with impaired hearing and balance. This was a .45 caliber rifle, barrel 13/16" across flats with 11/16" breech threads...

Scot, I'm glad you raised this topic:  awhile back, I'd made a trade for an unfired Cherokee with both .32 & .45 barrels, for The Bride's first ML, and she asked me to do some minor modifications to make it look a little more traditional, and pleasing to her eye.

So, since the topic at hand is the Seneca breech plug, and the Cherokee is, from what I'm told, virtually identical, I have a related question:

what in the heck is the ~1/4" dia plug on the off-side of the (Cherokee) breech plug, in the body of the plug (not forward in the threaded area of the plug, so can't be for indexing; this is in the chamber area of the body of the plug)?  Could/would this be a "blowout" plug, against an incidence of catastrophic failure, designed to direct failure and gases away from the shooter, or is it something else entirely?

[Bob Roller]

Caution -
The following is regarded Politically Incorrect amongst muzzle loader shooters.

Consider reading December, 1985 ... Entire patent breech and threaded portion of barrel separated, striking the shooter in the head . . . notch at the root of the thread concentrated stresses to about 1-1/2 times normal level, in the thin barrel wall.  Lost his left eye, had brain damage, with impaired hearing and balance. This was a .45 caliber rifle, barrel 13/16" across flats with 11/16" breech threads...

Scot, I'm glad you raised this topic:  awhile back, I'd made a trade for an unfired Cherokee with both .32 & .45 barrels, for The Bride's first ML, and she asked me to do some minor modifications to make it look a little more traditional, and pleasing to her eye.

So, since the topic at hand is the Seneca breech plug, and the Cherokee is, from what I'm told, virtually identical, I have a related question:

what in the heck is the ~1/4" dia plug on the off-side of the (Cherokee) breech plug, in the body of the plug (not forward in the threaded area of the plug, so can't be for indexing; this is in the chamber area of the body of the plug)?  Could/would this be a "blowout" plug, against an incidence of catastrophic failure, designed to direct failure and gases away from the shooter, or is it something else entirely?

Let's go back in time to the early 1970's. A magazine was started by the late John D.Baird to call attention to the dangerous
practices of over stressing these cast breech plugs and the T/C was notorious for over tightening them so the top flat on the plug
would match the top flat of the barrel. I remember that terrible incident about the one that blew out and the brain damage to the
shooter.This type of thing was fueled by the fallacy that enough black powder couldn't be loaded to blow one of these guns up.
In addition to the over tightened breech were the problems created by using a 50 caliber plug in a 45 caliber barrel and snagging the cleaning
patch. This company knew NOTHING about muzzle loaders and marketed a potential trap. To those who paid attention,Baird's magazine
called "The Buckskin Report"was a real help. It is my understanding that T/C was incorporated with a low level of liability but a lawyer
should address that question.I think it goes to the level of payment in the event of a blown gun and a consequential lawsuit.
The threaded plug in the left side of the plug is NOT a blowout plug but is a cross drilling to facilitate cleaning if needed. Many of the best
English long range rifles have cross drill breech plugs but they aren't obvious and are not removeable and are frequently covered with
engraving. I have seen X rays of these plugs showing that type of construction.In these English guns it was part of a design to prevent very
high pressures on the base of the nipple.
Some of the T/C plugs if shot with artificial powder would  get a rust ring going between the gap in the barrel threads and the shorter
length of the plug and there were some separations due to that high level of corrosion.
No one believes this was a deliberate attempt to market and poor product but lack of knowledge and not consulting with those of us who
did know brought about these low and high level disasters.

Bob Roller

[Dave Patterson]

Ah:  thank you, Mr R.

[Scota4570]

The clean out plug does not worry me.  The meat remaining, in the barrel,  around the breech plug threads is only 0.060.  The same thickness as a writing tablet cardboard backing I just measured. The fact that it was fired and did not blow up surprises me.

[BOB HILL]

I personally feel it was unsafe as originally built and would explain this to my friend and suggest he abandon this project......Bob

[Hungry Horse]

O.K. I have to weigh in on this one. I have been shooting black powder since the early seventies when these guns were so highly sought after that there was a waiting list at most dealers. They were the hot setup for women, kids, and hardcore hunters. I have literally shared the firing line with hundreds of them, and never witnessed a failure. I know T/C made some bonehead moves over the years, but I feel the Seneca, and Cherokee, offerings were safer than many other well known production guns. The bottom line is you can't fix stupid. I have seen several stupid people blow up muzzleloaders that were perfectly safe weapons, by just doing stupid things.

  Hungry Horse

[Daryl]

When I rebarreled my wife's Seneca with a GM .45 barrel, I did not record the plug threads used. I do know there is no gap between the end of the plug and the inner shoulder and that the threads were cut by Green Mountain, not me. Everything seemed a 'nice fishing boat'. (Hunky Dory)

[Scota4570]

The GM barrel is 5/8x18TPI.  The TC is 11/16 x20.  They did that to make gunsmithing more difficult.  The hole in the middle of the TC plug is to large to re-thread it to the smaller 5/8 thread safely, IMHO.

Nobody has the replacmenet plugs that fit the GM barrels, or a GM barrel for that matter. I am not interested in making this plug from scratch, since it has goofie contours.   

Unless I am 100% convinced the work I do is safe I will not proceed.  This falls in that catagory.

If anyone has one of the replacement plugs that track markets I'd be interested.  The guy who makes them is between shops and is not delevering right now.

[Bob Roller]

O.K. I have to weigh in on this one. I have been shooting black powder since the early seventies when these guns were so highly sought after that there was a waiting list at most dealers. They were the hot setup for women, kids, and hardcore hunters. I have literally shared the firing line with hundreds of them, and never witnessed a failure. I know T/C made some bonehead moves over the years, but I feel the Seneca, and Cherokee, offerings were safer than many other well known production guns. The bottom line is you can't fix stupid. I have seen several stupid people blow up muzzleloaders that were perfectly safe weapons, by just doing stupid things.

  Hungry Horse

The smaller bored versions of these T/C rifles seldom failed due to the small charges used in them.
Corrosion from perchlorated powder was another thing. The "Buckskin Report" articles condemned
the bigger caliber versions and the use of the Hawken name as a marketing strategy.I recall a couple
of knuckleheads at Friendship using 180 grains of 3fg in a 58 caliber T/C and the concussion was
disturbing to both myself and Bill Large because we were close to them when they fired the rifle.
Bill told them they didn't know what they were doing and I asked them if they ever got a shot on the target
with that load.They didn't know.
Later,when it became apparent these guns were catching on,Bill started making barrels for replacing the ones
that came on the guns.He also made the breech plugs to match the standing breech so that danger was
eliminated entirely.
   I just checked the 11/16x20 thread and it IS a special thread in the current Travers catalog.

Bob Roller

[Turtle]

Bob,
What is "Perclorated powder" please?
 I do know TC breechplugs are a pup to remove. I had to buy  special breechplug wrenches to hold the plug. 2 sizes I think. I bought my wife a Seneca and carry it sometimes hunting because it's so light and handy. It Sure does smite the cheek though.
                                           Turtle

[JCKelly]

"Pyrodex" is a brand of artificial powder that uses potassium perchlorate, rather than potassium nitrate (saltpeter) to supply the oxygen.

Using perchlorate powder is somewhat like using old chlorate (corrosive) primers on steroids, with respect to what it does to steel.

[Daryl]

Excellent response, JCKelly - only a few words and nothing that could possibly be argued with.

[Dphariss]

I spent a lot of time in the editorial offices of the Buckskin Report during this time. Living in the immediate area and writing for John. People who shoot and collect the TC Hawken, especially the early ones, have no idea what was going on at the time... Had the plaintiff's  lawyers had been a little smarter and did some research there would likely be no TC "Seneca" or other products much less a TC  today..... But barrel and firearms manufacturers get to use the "handloader" defense. Its always the fault of the person loading the firearm, cartridge or ML if the ammo is not factory loaded. So ML shooters are immediately suspect as having not loaded it right since the "event" is usually impossible to recreate.
If I am at a match and someone is shooting a factory made I try to stand directly behind them. 
Dan