Breech plug question
01-27-2016, 07:01 PM
#21
Boone & Crockett
Join Date: Aug 2004
Location: Idaho
Posts: 11,703
i'm not sure you would consider a white nipple a breech plug i would anyway i have been installing by hand with the bp tool then back off just a tad but never seen any evidence of blow back on the threads i would think with enough threads and some type of grease there wouldn't be any gases getting thru ? any thoughts ?
01-27-2016, 07:06 PM
#22
Nontypical Buck
Join Date: Aug 2008
Location: Rapid City, South Dakota
Posts: 3,732
Normally i install breech plugs with a 1/4" ratchet, an extension, and a socket. Normally, i make them tight. This evening i used a calibrated torque driver made by Wiha to install a breech plug several different times with increasing torque.
Started at 22 inch lb. After torquing the plug i put the ratchet on it, and made it tighter. The torque was increased step by step. Each time, i tightened the plug using the torque driver, then made it tighter with the 1/4" ratchet. After 38 inch lb with the torque driver, using the 1/4" ratchet did not further tighten the plug.
It seems my normal way of tightening breech plugs results in a tightening of a torque of around 38 inch lb.
Beings how hand tightened plugs work just fine, the minimum torque requirement would be almost zero inch pounds.
Started at 22 inch lb. After torquing the plug i put the ratchet on it, and made it tighter. The torque was increased step by step. Each time, i tightened the plug using the torque driver, then made it tighter with the 1/4" ratchet. After 38 inch lb with the torque driver, using the 1/4" ratchet did not further tighten the plug.
It seems my normal way of tightening breech plugs results in a tightening of a torque of around 38 inch lb.
.........would it be even close to say.......... 80ip is probably the maximum torque needed for any breech plug? If that can be agreed to, then the next question would be, what would be the minimum torque?
01-27-2016, 07:06 PM
#23
Nontypical Buck
Thread Starter
Join Date: Jul 2014
Location: Near a lake with no fish
Posts: 1,077
01-27-2016, 07:09 PM
#24
Nontypical Buck
Thread Starter
Join Date: Jul 2014
Location: Near a lake with no fish
Posts: 1,077
Normally i install breech plugs with a 1/4" ratchet, an extension, and a socket. Normally, i make them tight. This evening i used a calibrated torque driver made by Wiha to install a breech plug several different times with increasing torque.
Started at 22 inch lb. After torquing the plug i put the ratchet on it, and made it tighter. The torque was increased step by step. Each time, i tightened the plug using the torque driver, then made it tighter with the 1/4" ratchet. After 38 inch lb with the torque driver, using the 1/4" ratchet did not further tighten the plug.
It seems my normal way of tightening breech plugs results in a tightening of a torque of around 38 inch lb.
Beings how hand tightened plugs work just fine, the minimum torque requirement would be almost zero inch pounds.
Started at 22 inch lb. After torquing the plug i put the ratchet on it, and made it tighter. The torque was increased step by step. Each time, i tightened the plug using the torque driver, then made it tighter with the 1/4" ratchet. After 38 inch lb with the torque driver, using the 1/4" ratchet did not further tighten the plug.
It seems my normal way of tightening breech plugs results in a tightening of a torque of around 38 inch lb.
Beings how hand tightened plugs work just fine, the minimum torque requirement would be almost zero inch pounds.
01-30-2016, 04:18 AM
#28
Nontypical Buck
Thread Starter
Join Date: Jul 2014
Location: Near a lake with no fish
Posts: 1,077
Ron's test with a non-finger tighten breech plug appears to be about what most probably tighten. Even finger tightening provides a force, or torque. Flat faced mating appears to be the issue, where the forces create either galling or welding of threads because of poor thread design, allowing blow back into the threads. Thus the reason some are taping plugs.
01-30-2016, 04:55 AM
#29
Nontypical Buck
Join Date: Aug 2008
Location: Rapid City, South Dakota
Posts: 3,732
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. This seems to be the same way the new rear sealing plugs work.
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.
Because it seemed like this plug might never wear out, one more change was done to the plug. 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.
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. This seems to be the same way the new rear sealing plugs work.
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.
Because it seemed like this plug might never wear out, one more change was done to the plug. 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.
01-30-2016, 04:57 AM
#30
Nontypical Buck
Join Date: Aug 2014
Location: gilbert az
Posts: 1,168
yes i shoot swiss 3f in my pistols and i shoot schuetzen 2f in my rifles so when i said black powder i was referring to one or the other depending on which shoots better? i really started using the 777 when i lived back east where it was a lot more humid and inclimate weather so it's just one less powder i have to stock or have on hand now that i live out west.