Breech plug question

[Squeeze]

I never liked the pink (gas) teflon. It was always so much thicker, and made the BP very tight all the way in. Even the white stuff, I have to be carefull not to overlap too much. And It never seems to come back out on the plug. I get in there with a brush and swipe the teflon threads back out usually.

 

[WV Hunter]

I never liked the pink (gas) teflon. It was always so much thicker, and made the BP very tight all the way in. Even the white stuff, I have to be carefull not to overlap too much. And It never seems to come back out on the plug. I get in there with a brush and swipe the teflon threads back out usually.

I use the pink, cause its what I have. I have noticed that in my rifles, they vary in how hard/easy the BP installs/removes. My .45 Elite, the plug goes in tighter and when I remove it it leaves much of the tape behind. My .50 Elite goes in easier and the BP comes out looking like the one in SL's pics, the tape still on the BP. Both have Lehigh BP's. I do not torque them, just tighten down snug plus a smidge more. I do leave the tape long to create that seal as SL describes... learned that from him :yeah:
Both work as designed, keeping the fouling from the threads, so I guess I must be doing something right.

 

[ronlaughlin]

.......Ron just tested one of his rifles breech plugs (reported elsewhere) He reported he checked it multiple times and indicates his normal torque procedure is about 38 inch pounds.

Normally, upon returning home from shooting a rifle, it is placed in a vise, the breech plug is removed, and the rifle cleaned. To remove, and install the breech plug, a short 1/4" ratchet is used, along with an extension, and a socket. When installing the plug, it is turned in to the rifle until it hits bottom, and it is 'tightened'. No torque measurements are made.

The other evening i used a torque driver, that i use to install scopes, and stocks, to install a breech plug. Evidently it had been last used to install rings, because it was set for 22 inch pounds. After using the torque driver to install the plug, i put the normal tool to work, and used the short 1/4" ratchet to 'tighten' the plug. The ratchet turned the plug quite a ways, and made it tighter. Then the torque setting was increased to 24 inch pounds, and the plug was installed again using the torque driver. Once again the plug was tightened further using the ratchet. Increasing the torque settings on the driver in steps, the plug was installed, and tightened using the ratchet. Each time, the ratchet made the plug tighter.

When the torque setting on the driver was 36 inch pounds, the ratchet made very little 'extra tightening' of the plug. When the torque setting was increased to 38 inch pounds, the ratchet did nothing.

My assumption is, that my normal way of seating breech plugs, tightens them to about 38 inch pounds.

 

[Squeeze]

38 inch lbs is just over 3 lbs. that might be closer to my typical. I barely go over finger tight usually and have never had any noticeable problems. On the .32 conversion (standard Knight BP) I was so loose at least once, I had a carbon buildup on the mating surface. I cant see any gas cutting, and it never fully migrated through the threads. This was with grease on the BP. I have since switched to teflon predominantly, and this, coupled with watching closer seemed to fix it. Cleaning the carbon off the mating surface was a challenge I remember. The lessons you learn the hard way, are usually well remembered.

 

[ENCORE50A]

.......Ron just tested one of his rifles breech plugs (reported elsewhere) He reported he checked it multiple times and indicates his normal torque procedure is about 38 inch pounds.

Normally, upon returning home from shooting a rifle, it is placed in a vise, the breech plug is removed, and the rifle cleaned. To remove, and install the breech plug, a short 1/4" ratchet is used, along with an extension, and a socket. When installing the plug, it is turned in to the rifle until it hits bottom, and it is 'tightened'. No torque measurements are made.

The other evening i used a torque driver, that i use to install scopes, and stocks, to install a breech plug. Evidently it had been last used to install rings, because it was set for 22 inch pounds. After using the torque driver to install the plug, i put the normal tool to work, and used the short 1/4" ratchet to 'tighten' the plug. The ratchet turned the plug quite a ways, and made it tighter. Then the torque setting was increased to 24 inch pounds, and the plug was installed again using the torque driver. Once again the plug was tightened further using the ratchet. Increasing the torque settings on the driver in steps, the plug was installed, and tightened using the ratchet. Each time, the ratchet made the plug tighter.

When the torque setting on the driver was 36 inch pounds, the ratchet made very little 'extra tightening' of the plug. When the torque setting was increased to 38 inch pounds, the ratchet did nothing.

My assumption is, that my normal way of seating breech plugs, tightens them to about 38 inch pounds.

Thanks Ron

 

[Squeeze]

I think teflon alone must subtract a few pounds at least from true reading. With grease, theres virtually no thread resistance till bottomed. With the tape, theres always a few pounds of resistance through the threads, so if your going for the usual ~10 lb seat, you would seem to have to seat a teflon wrapped plug extra to match a greased plug. There was a recent BP dispute on another forum, and one guy machined off the mating surface of a BP, and shot several times. the threads alone sealed completely. BUT most agreed that continued use would eventually (probably sooner than later) lead to gas cutting, and barrel/BP damage.

On a similar note, the admins on another forum are now collecting old, damaged, and unwanted barrels. (mostly from smokeless conversions, and or worn barrels) to do failure testing. Im eagerly awaiting these test results.

 

[GM54-120]

On a similar note, the admins on another forum are now collecting old, damaged, and unwanted barrels. (mostly from smokeless conversions, and or worn barrels) to do failure testing. Im eagerly awaiting these test results.

The videos will be quite interesting to watch.

 

[JStanley]

On a similar note, the admins on another forum are now collecting old, damaged, and unwanted barrels. (mostly from smokeless conversions, and or worn barrels) to do failure testing. Im eagerly awaiting these test results.

The videos will be quite interesting to watch.

GM - if possible, post a link to the results when they become available. Thx.

 

[ronlaughlin]

Me, i have shot only one rifle that had a perfect seal between the plug, and the barrel. Never have shot smokeless, nor have i ever shot a custom rifle. To try and cure the leakage of the other rifles, i have used long handled wrenches, and really torqued the plug tight. So tight in fact, once it seemed like i wouldn't be able to remove the plug; never did that again. Another thing i tried, was JStanley trick of making the rim thin.

The plugs with the thin rim leak just as much as the standard plug. These days i don't bother with trying to seal the nose of the breech plug to the barrel. It isn't necessary, and can't be done anyway. Because i shoot Blackhorn, just one wrap of tape on the plug is good. One wrap of tape makes the seal, and stops the flame. It is overlapped just so barely. If the flame has no where to go, it doesn't.

That plug has been shot in 5 different rifles, hundreds, and hundreds of times. There is zero evidence of flame cutting on the nose, or the threads. Even though there is a poor seal at the nose, it still doesn't get flame cut, because there is no flame flying past, and cutting, because of the seal further up at the threads. Nor do the threads get flame cut.

The only place where this plug is flame cut, is in the primer seat.

A quick halt to the flame cutting was done by cutting 0.020" off the nose because of tight head space, and using a metric o-ring under the primer.

One more change was done to the plug, so it would last, and last. A vent liner was added. What is being shown here is a breech plug that will last quite a long long time without need of replacement. Whilst using this plug, one has no need, to be concerned about torque, just snug it up.

The one plug/rifle combination that made a perfect seal when i shot it, was the Accura V2, and the QRBP when new. This perfect seal is accomplished when the plug is torqued at negligible pound inches, by the shooter.

 

[bestill]

Rear sealing breech plug design is the answer100 % sealing

 

[52Bore]

Encore:
Sorry, I too have no torque spec.
When I was reading, I was thinking Remington torques because they don't want people to remove (you stated that along with Ultimate) - in a production environment (like automotive) everything has a torque spec. The reason, the bolts are holding something together (valve covers, door hinge, etc.). I don't see that with a breech plug, it just bottoms out. What requires a torque that doesn't keep something together (right now I can't think)?
Here is my take on breech plugs that mate up flat surface to flat surface.
Breech plugs are made of the same material as the barrel (at least Knight is) and that's not really a good thing marring two same metals together time-and-time again - they tend to gall which will not allow it to seal as well. We're talking very small amount here, but we're also putting a tremendous about of pressure rearward as the bullet exits. No matter how tight you torque, your pushing the face surfaces tighter - but if it's marred with galling or factory machine marks, it really will not matter unless you begin plastic deformation of either face. I think some mfg years ago used a brass or copper face on a breech plug??
I would doubt (someone may actually know) that breech plug threads are better than class 1 threads - 75%, maybe class 2, but I doubt 3. Not talking tap drill diameter, I'm talking clearance between breech plug thread and tapped hole threads, each thread. That's why people can use teflon tape, get the thread fit tight and it will strip off. But, mfg. don't what this fit so tight because it's alway going in/out. A less class fit will also allow more 'crud' into the threads.
I have removed breech plugs on 150 year old percussion guns that looked as new as today. Yes, they used grease,/oil ,but it was the fit (tolerance between each thread) that is so small - nothing ever got in there to rust. Who knows how many rounds these original guns have fired black powder over their life, but my in-line will be covered after a days shooting.
Sorry for going long..

 

[52Bore]

Rear sealing breech plug design is the answer100 % sealing

Teach us about this?

 

[52Bore]

Encore, I apologize if you already know all this.

 

[bestill]

cant post pics my photobucket is down.
so most smokeless muzzleloaders were built with a savage style front sealing breech plug and they had tremendous gas cutting of sealing shoulders beings its hit direct with chamber pressure instantly.
many have since redesigned builds to use a rear sealing breech plug with a sealing shoulder that is just in front of hex . this kinda works like vent liner and flame channel. when powder ignites the pressure forces thru vent filing flame channel and then hitting primer this process is quick but the primer isnt subjected to near the pressure as the chamber.

so same theory with rear sealing plug upon ignition pressure spikes and is slowed down trying to travel up threads to rear seal that delayed pressure reduces pressure actually put on rear seal cause bullet is leaving and pressure is dropping. this all happens extremely fast but it works.
couple examples arrowhead sporting goods 9/16-18 asg breech plug
hankins custom rifles breech plugs

 

[Grouse]

cant post pics my photobucket is down.
so most smokeless muzzleloaders were built with a savage style front sealing breech plug and they had tremendous gas cutting of sealing shoulders beings its hit direct with chamber pressure instantly.
many have since redesigned builds to use a rear sealing breech plug with a sealing shoulder that is just in front of hex . this kinda works like vent liner and flame channel. when powder ignites the pressure forces thru vent filing flame channel and then hitting primer this process is quick but the primer isnt subjected to near the pressure as the chamber.

so same theory with rear sealing plug upon ignition pressure spikes and is slowed down trying to travel up threads to rear seal that delayed pressure reduces pressure actually put on rear seal cause bullet is leaving and pressure is dropping. this all happens extremely fast but it works.
couple examples arrowhead sporting goods 9/16-18 asg breech plug
hankins custom rifles breech plugs

Pretty impressive information, thanks for sharing that!!

 

[long shot]

how does it work for black

 

[Grouse]

how does it work for black

I would think the same way. Why would you think it would be different? The reason for mentioning smokeless was to validate what he was saying with an example.

 

[52Bore]

bestil:
I've never seen a Savage breech plug, but I assume it has a cylindrical portion up into the bore - which leaves only the grooves for the fouling to travel before getting to the threads. So, I think I follow you until the back seal part/description. What prevents the fouling from entering the threads at the front of the breech plug?
I know you shot BH209 (similar to smokeless in respect to reside), but what would Black, 777 or other subs do with this type plug?

 

[Grouse]

bestil:
I've never seen a Savage breech plug, but I assume it has a cylindrical portion up into the bore - which leaves only the grooves for the fouling to travel before getting to the threads. So, I think I follow you until the back seal part/description. What prevents the fouling from entering the threads at the front of the breech plug?
I know you shot BH209 (similar to smokeless in respect to reside), but what would Black, 777 or other subs do with this type plug?

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.

 

[52Bore]

He doesn't use any tape.