Breech plug question

[52Bore]

That's what I recall. That's what intrigues me.

 

[52Bore]

[/quote]
I'm not Bestill but I shot and owned many savage muzzleloaders. When shooting 777 out of the savage I wrapped my plug with tape and it stopped all fouling from reaching the threads. I'm sure grease would do the same but I like using the tape.[/quote]

Just curious, please don't take this offense but, this comment make me assume you have not built an In-line ML?

 

[Grouse]

He doesn't use any tape.

The reason he doesn't use tape cause he shoots BH209. If he shot black powder or 777 he would need to.

 

[Grouse]

I'm not Bestill but I shot and owned many savage muzzleloaders. When shooting 777 out of the savage I wrapped my plug with tape and it stopped all fouling from reaching the threads. I'm sure grease would do the same but I like using the tape.[/quote]

Just curious, please don't take this offense but, this comment make me assume you have not built an In-line ML?[/quote]


No offense taken, I have not. Not sure what that matters when talking about a front sealing or rear sealing breech plug. Shoot your Knight with nothing on the breech plug threads and shoot black powder. I'll bet those threads are covered in fouling. Do that same test with BH209 I bet they are not.

 

[52Bore]

Please neither of you start.

I recall bestill telling me this at Friendship, but I didn't follow and now that its come back up - my brain remembered I never understood adn I would like to learn.
Getting late I understand, no hurry.

 

[52Bore]

No offense taken, I have not. Not sure what that matters when talking about a front sealing or rear sealing breech plug. Shoot your Knight with nothing on the breech plug threads and shoot black powder. I'll bet those threads are covered in fouling. Do that same test with BH209 I bet they are not.

I use copper never-seize and I do get a black never-seize breech plug when it comes out.
Thanks

 

[Grouse]

No offense taken, I have not. Not sure what that matters when talking about a front sealing or rear sealing breech plug. Shoot your Knight with nothing on the breech plug threads and shoot black powder. I'll bet those threads are covered in fouling. Do that same test with BH209 I bet they are not.

I use copper never-seize and I do get a black never-seize breech plug when it comes out.
Thanks

There's no doubt a rifle builder will explain this way better then me. But a front sealing plug and a rear sealing plug both have threads that are married together. A rear sealing plug has some threads that are exposed but obviously not all. If you tape your rear sealing plug when shooting black powder or 777 it will keep the fouling from entering the threads that are married together. Then you will have no problem removing your plug.

The problem with your never seize is it get hot and runs. It won't do a good job of sealing those threads and keeping them clean from fouling. The tape will work much better especially in heat and when your doing a lot of shooting.

 

[GM54-120]

Here are some pics of LRMP plugs, Savage type 209 plugs and rear sealing plugs

http://www.hankinscustomrifles.com/muzz ... omponents/

 

[bestill]

The type powder being use isn't a factor.

I only referenced smokeless because of high pressure against front sealing surface and it quickly degrades seal.
This happens with all powders just faster with higher pressure.

Its obvious the front sealing leaks or we wouldnt get black fouled breech threads so we use tape or antisieze to keep plug from getting stuck or very hard to move. This is on knight,tc,savage and all front seal plugs.
Tape and antiseize don't seal its just a release agent for plug removal.
As mentioned a 75% machine thread when tight leaves a pathway for pressure to flow spiralling up the thread and out once the front seal is degraded.

With a rear sealing plug still use grease or tape or something as a release agent but the rear seal doesnt get hit directly with chamber pressure and will hold and if it doesnt leak there's less flow thru threads and less fouling in breech threads.

 

[ENCORE50A]

The problem with your never seize is it get hot and runs. It won't do a good job of sealing those threads and keeping them clean from fouling. The tape will work much better especially in heat and when your doing a lot of shooting.

Permatex makes an anti-seize called Nickel. Nickel is designed for extreme pressures and high heat, up to 2,400°F. Its main use is for stainless steel, titanium and nickel. We should find out how that works......

Although there have been comments, 52bore and bestill brought up great points. Now I have no clue about the rear sealing breech plugs, however it sounds very interesting. Are the flat sealing surfaces the problem? Are tighter thread tolerances better? What force (torque) would there be using Teflon tape? Are we making up for poor engineering by using tapes, grease or anti-seize?

In general, most shooters do not think of these things and/or, normallly not discussed in depth. Yet, they exist. I like where this is now going.....

 

[52Bore]

With a rear sealing plug still use grease or tape or something as a release agent but the rear seal doesnt get hit directly with chamber pressure and will hold and if it doesnt leak there's less flow thru threads and less fouling in breech threads.

Yes, the 'something' is preventing the fouling from entering - once there's no where for the fouling to go, it stops penetrating. That's why all the Engineers with all the makers are like me (engineer) and think if you can stop it before it even gets there on the front end, all is good. From my perspective, the rear seal makes no since and sounds like ?? - who came up with this philosophy?. Although it seems that way to me, I'm still listening . Maybe there are other engineers out there to weigh in on their thoughts?
Savage plug has the protrusion up into the bore to prevent reside into the threads. When I saw the Redemption, I thought great idea - makes since to put the threads on the OD, then protrude into the bore and use an o-ring - neat idea. But, butt ugly on the outside.
When I made my 1st in-line (Omega) I took the Redemption idea and basically did the same thing. Even with Black, I think I could not put anything on the retaining nut threads. But, the plug into the bore is tight after a days shooting.
Here is what, I'm taking about.


I what to try a one-piece, protrudes into the bore with a o-ring. But, I want to understand your rear seal, as I don't care to try it - but so far it doesn't make since. Maybe only way to find out with Black is try.
Thanks

 

[Lee 9]

http://www.americanboltcorp.com/tech/techtorque.pdf
If you really feel the need then the standard torque chart should answer the question.

 

[sabotloader]

I have been watching this thread on and off for awhile but when Bestill mention the rear sealing BP it really did peak my interest. I had the same questions that 52bore brought up - even had a discussion with another forum member about it. I just could not figure out how it might work with T7 if the threads were exposed to the blowback pressures of shooting. Even if they were greased or taped. Neither of these two products could/would handle heat and pressure and easily break down the two products. It makes sense what Bestill said about aiding the release of the plug.

I am still not sure if the rear sealing plug would work over time and several shots that might be taken in a range session. Guess I would have to try it to believe it.

I do no and feel that I in most cases get near 100% seal at the nose if the BP with the aid of the compression and torque of the BP that I use. It seems evident to me when I remove the plug after a round of shooting. Most often the plug is clean on the outside. This is really visible with the original 17-4 breech plugs that Lehigh made. Even the tape that is pulled from the breech with the brush is still white. So I really do believe I am getting a nearly perfect seal.

Again shooting T7 or the Pyros I am having a hard time believing that the blowback pressure would not work its way back up the threads of the BP and eventually cause the plug to seize whether it was taped or greased. Hunting with a rear sealing plug certainly would not be a problem but I envision a range session might be.

Really wish I had away to try it! of course none of the rifles I have are rear sealing. I do know what the results might be if I shot a 'torqued' bare front sealing plug in a range session. The blow back would never reach the rear of the plug but the first group of threads it would and the plug would be seized. Married threads have been mention but if you have ever installed a exhaust manifold - torqued the threads to marry them and then a few years later try to get those bolts out???? Probably not a good analogy but...

 

[WTM45]

As currently designed, the removable breech plug is considered by the manufacturers to be an expendable item which is easily replaced. Most every manufacturer who designs their plug to be removed for maintenance can and do provide replacements. Removable plugs have a service life.

So, since the tolerances chosen in design and manufacture GREATLY take in to consideration the user will be wanting to or will be required to remove the plug, maintain it, inspect it and then reinstall it there is little need to dig much deeper into their design. Unless one just has to satisfy some itch.

Plugs have to be designed at a moderate (considerably less than tightest) tolerance, knowing that the vast percentage of users will be doing this function by hand. Otherwise there would be a completely different means of installation at manufacture chosen which would be more permanent. That would most certainly involve materials manipulation with temperature or electricity.

 

[chaded]

If my understanding is correct, the rear sealing plug was never meant to be a way to seal the threads from getting blowback. Again if my understanding is correct (feel free to correct or add to), the rear seal was made for smokeless guns because the savage plug had a tendency to get flame cutting on the front sealing surfaces. Whether that was from getting some carbon build up on the surface or not having the surfaces mate correctly. I am pretty sure the gas will follow the threads with a rear sealing plug. I am not an expert or claim any of this is the best design or whatever but I think this is what I read the reasoning was for the rear sealing plug when it came out for the smokeless guns.

 

[Squeeze]

There was recently a big controversy about pretty much this on another board. Mostly between builders, and their following. One thing you have to say about Hankins, he does prove his own theories. And So far has proven, he does build a better mousetrap. This may be a bit lengthy, but explains things pretty well.



[youtube]ijEEsOX1KV4[/youtube]

 

[sabotloader]

There was recently a big controversy about pretty much this on another board. Mostly between builders, and their following. One thing you have to say about Hankins, he does prove his own theories. And So far has proven, he does build a better mousetrap. This may be a bit lengthy, but explains things pretty well.



[youtube]ijEEsOX1KV4[/youtube]

As you view this video listen to his thoughts that threads will or can seal a BP - He indicates the plug needs to be sealed at the front or the rear - but the rear is more positive because of the stretching of the barrel.

As far as the stretching effect on the nose of the plug if there is enough surface mating between the nose of the plug and the shoulder in the barrel - you may still maintain a seal... Which I THINK - I am getting in my Knights

This is not the picture I was looking for but it is not bad... this is a Remington 700ML plug removed after shooting a range session. The nose of the plug in combination with the tape did exactly what I believe it should do. How much blow back made it back up the threads of the plug even though the barrel stretched on shooting allowing blowback accesses to the threads.



I actually have a better pic - but Photobucket is being Photobucket again...

 

[Squeeze]

Arent pretty much all plugs front sealing? even break actions, I think are just timed to have the rear seal close, but designed to have front seal. Some have an added O-ring at one or both ends. Those plugs almost seal both ways. Most Knight, Remington, savage, etc type plugs are all front sealing. Some of the new customs are now using rear sealing plugs.

 

[sabotloader]

Arent pretty much all plugs front sealing? even break actions, I think are just timed to have the rear seal close, but designed to have front seal. Some have an added O-ring at one or both ends. Those plugs almost seal both ways. Most Knight, Remington, savage, etc type plugs are all front sealing. Some of the new customs are now using rear sealing plugs.

my thoughts are currently most plugs are front sealing

I think the customs are moving to the Hankins type plug but most customs are not shooting BP or BP subs - other than BH which is really a smokeless - so it works great in a rear seal...

Which leads me to another problem - I wonder why the Ultimate is not suppose to shoot BH? Shooting BH actually seized his BP. I know he has explained it but I do not remember as it did not apply to me.

 

[52Bore]

Sorry Encore, we've gotten off your original question.

Those that have front face seals. Have you ever coated the front of your breech plug, install like normal and remove? A thin coat of Prussian blue works best, but a black magic marker will do - coat it good. You will see the amount of contact you have.

They used to make spray graphite and teflon, BPCR guy tried it years ago on PP bullets - but I don't think it improved their groups, but it was tried.
Has anyone ever tried either of these sprays on their breech plugs thread, you could probably also spray the thread in a break-open or Omega - but might be hard in a bolt gun.
This seems like it would certainly slick the threads up for removal and coat the threads to maybe fill some of the void space in the threads.