Breech plug torque

[flatsguide]

What’s a good torque for a 5/8” breech plug? Some plugs I removed and reinstalled took so much effort to line things up that you could have slowed the earths rotation. What about using something like 20-25 foot pounds and green Loctite. Not using the Loctite for sloppy work. Really don’t want to ding up a hooked breech plug. Any ideas and thoughts are appreciated.
Cheers Richard

[Hank01]

I pretend it's a spark plug and tighten accordingly, maybe a little more to get things lined up. Never used loc-tite though but rather just a dab of never seize.

Hank

[Mike Brooks]

run a tap and die in the hole and on the plug. Problem solved.

[Daryl]

I've only tightened them up that far - tight. It's easy to get too technically specific in this hobby.

[Bob Roller]

Don't tighten it to the point the twist of the rifling changes like a reverse gain twist.
Bob Roller

[P.Bigham]

On a original I had the breech plug could be unscrewed by hand.

[Tim Ault]

IMO  don’t think they need to be gorilla tight , not like it’s gonna vibrate loose or unscrew itself my unscientific thoughts only

[Angus]

Certainly hope nobody is missing the most important point that the plug face should seal off the bore.

[Dphariss]

What’s a good torque for a 5/8” breech plug? Some plugs I removed and reinstalled took so much effort to line things up that you could have slowed the earths rotation. What about using something like 20-25 foot pounds and green Loctite. Not using the Loctite for sloppy work. Really don’t want to ding up a hooked breech plug. Any ideas and thoughts are appreciated.
Cheers Richard

There is WAY more to fitting a breech than torque. If not fitted right and then removed at some later date it will invariably turn past the index.
Some of the factory mades have the breeches greatly over torqued by machines. Some so tight that the patent breech was stretched to the point that some would break off and leave the threaded portion in the barrel. Most barrels that come breeched are sloppily done.

Forgive the lousy camera work. I spent a LOT of time well over an hour, fixing the barrel makers “breeching” so that I could make a rifle around this barrel without guilt.

[JLayne]

A few years ago at the Kempton Gunmakers Fair (when it was still at the original venue) I sat in on a class on installing a breech plug taught by a gentleman named John Cholin, who I believe was a retired engineer. If I remember his opinion correctly, he stated that the breech plug, while tight, should never be so tight that it requires anything more than a large crescent wrench to remove it. He said that torquing them down with a cheater bar could damage the threads. I believe the crescent wrench he was using during the demonstration was around 12” or so in length, but don’t quote me on that.

Jay

[Mike Brooks]

Kit Ravenshire used to fit his plugs finger tight.

[Bob Roller]

On a original I had the breech plug could be unscrewed by hand.
[/quote

So did I.It was a pristine 58 caliber Springfield and I was surprised at the ease of removal.I suppose the fact that the bullet could move
easier than the threaded plug kept me out of the hospital or mortuary .
Bob Roller

[smylee grouch]

Over the years I have fit several breech plugs and never gave torque a thought. Only thought about the end butting up to the shoulder in the bore and the flat corners lining up at the same time.

[wmrike]

I think that one of the things that makes removal of a factory install plug so daunting is that it is hard to get a good purchase on the barrel without boogering the edges of the flats.  I have a vise with long, leather-faced jaws that serves the purpose well.

The other thing to consider is that a garden variety 5/8" plug is minimally spec'd for 96 ft-lbs.  That's a bunch if you are wrenching on the plug with a 10 or 12 inch adjustable.  If you are fitting the plug yourself, you can opt for a "looser" fit.

[Eric Kettenburg]

I inwardly cry a little and often lube up my innards with a few good fermented barley beverages before dealing with one of Ed Rayl's.

Mike's advice is good advice and a good reason to keep those taps/dies on-hand.  Most of the commercial barrels sold with fitted breechplugs are obscenely tight.

[Bob Roller]

Going back in time to the early 70's,I recall breech plugs in TC rifles that were over tightened to align the flats of the octagon barrel with the breech plug that created a built in fracture line.Some of them blew up with bad injuries incurred.The Hawken Shop, when it was in St.Louis had their cast breech plugs X rayed and any detected flaws went back to the foundry. The production rifles that failed were assembled by people who had NO idea about what they were doing and the words "Stress Fractures" were not in their vocabulary.
The late Don Brown asked me about X raying and I told him about Art Ressel and the Hawken Shop and that I had seen X rays with flawed
plugs that never got used.The breech pressures on these long range 451's is much higher and other factors such as the nipple seats are
involved as well.Most on this forum are aware of these types of rifles but only a few shoot them in comparison to the more common long rifles but even though the long rifles work at much lower pressure levels,the installation of the breech plug IS the main thing between a
good time shooting and a fast ride to the ER and maybe the loss of an eye.I think Don Brown did have his cast plugs checked by X rays.
Bob Roller

[flatsguide]

Thank you very much for your informative replies and especially Dpharris’s video on fitting.
CheersRichard

[Marvin S]

Lots of them get hard to remove due to crushing the starter thread on the plug. Even a bottom tap won’t cut a thread all the way down. I always remove the starter thread from the plug since it should seal at plug face and the shoulder of the bore. Gasoila pipe dope and 10-20 ft lb is what I like.

[oldtravler61]

  What I don't get is why barrel makers. When they install the breech plugs. They never put never seize on the threads.
 But if you do buy a barrel with breach plug fitted.  Never think that it is done properly. 

[Mike Brooks]

  What I don't get is why barrel makers. When they install the breech plugs. They never put never seize on the threads.
 But if you do buy a barrel with breach plug fitted.  Never think that it is done properly.

Hoyt often does. Teflon tape at times too.

[smylee grouch]

Vice jaws clamped over the breech thread area can cause a lot of problems in removing the plug.

[flatsguide]

I’ve got an English project coming up later that will require a hooked breech. I got a piece of 1.75” diameter 8620 rod that I’ll make the plug and tang from. I’ll thread the barrel then when that’s out of the lathe I’ll machine the plug threads and keep the plug set up in the lathe until it is fitted.
Thanks again Richard

[B.Habermehl]

I’m really not a fan of anti seize compound on breech threads. It creeps and winds up in the shoulder between the tang and the rear of the barrel. Just about guaranteed to cause browning and blueing problems. If I were to use anything I’d use a dab of blue lock tight. It is designed to allow removal with normal hand tools and will protect the threads from corrosion even though it’s not it’s designed purpose. I normally use a 12 in wrench to snug everything up. Probably less than 50 foot pounds of torque. More like 30. Goodenschnuggen, not frigginbroken. BJH

[flatsguide]

Lol…..not like ‘tighten it down ‘til it strips and back off a quarter turn’

[Curtis]

I’m really not a fan of anti seize compound on breech threads. It creeps and winds up in the shoulder between the tang and the rear of the barrel. Just about guaranteed to cause browning and blueing problems. If I were to use anything I’d use a dab of blue lock tight. It is designed to allow removal with normal hand tools and will protect the threads from corrosion even though it’s not it’s designed purpose. I normally use a 12 in wrench to snug everything up. Probably less than 50 foot pounds of torque. More like 30. Goodenschnuggen, not frigginbroken. BJH

Brown the barrel and plug with clean threads and THEN apply the anti-seize compound upon final assembly!  Or brown separately and then assemble with anti- seize...

Curtis