What makes a Breechplug a Great BP?
01-09-2010, 04:17 PM
#71
Nontypical Buck
Thread Starter
Join Date: Jan 2009
Location: Northern Chautauqua Co. N.Y.
Posts: 2,976
Breechplug
It was below zero here last night and at day break, but by the time i made it out to shoot it was already over freezing. Supposed to be in the forties this next week, so weather will change here.
The load was 105g BH209, Harvester smooth sabot, 44 caliber 300g xtp, and Winchester shot gun primer.
Will shoot paper once, and then go hunting some more this next week. Won't be cold this next week, but will still be putting the modified breech plug to the test whilst hunting.
It was below zero here last night and at day break, but by the time i made it out to shoot it was already over freezing. Supposed to be in the forties this next week, so weather will change here.
The load was 105g BH209, Harvester smooth sabot, 44 caliber 300g xtp, and Winchester shot gun primer.
Will shoot paper once, and then go hunting some more this next week. Won't be cold this next week, but will still be putting the modified breech plug to the test whilst hunting.
(BP)
01-09-2010, 04:45 PM
#72
Nontypical Buck
Join Date: Aug 2008
Location: Rapid City, South Dakota
Posts: 3,732
Breechplug
The muzzle was covered by 2 pieces of black electrical tape. There are a couple of plausible reasons for the hang fires.
ONE.......The carbon in the flash channel wasn't drilled out all the way to the flash hole.
TWO.........It is recommended one use magnum primer with BH209, and i don't.
I think making a deeper concavity in the breech plug will help with this issue.
When i first got this rifle i started with the crush rib sabot, because that is what i use in my Omega. They were definitely too loose. These Harvester smooth sabot are as tight as i want to deal with.
The muzzle was covered by 2 pieces of black electrical tape. There are a couple of plausible reasons for the hang fires.
ONE.......The carbon in the flash channel wasn't drilled out all the way to the flash hole.
TWO.........It is recommended one use magnum primer with BH209, and i don't.
I think making a deeper concavity in the breech plug will help with this issue.
When i first got this rifle i started with the crush rib sabot, because that is what i use in my Omega. They were definitely too loose. These Harvester smooth sabot are as tight as i want to deal with.
01-09-2010, 05:13 PM
#73
Nontypical Buck
Thread Starter
Join Date: Jan 2009
Location: Northern Chautauqua Co. N.Y.
Posts: 2,976
Breechplug
The muzzle was covered by 2 pieces of black electrical tape. There are a couple of plausible reasons for the hang fires.
ONE.......The carbon in the flash channel wasn't drilled out all the way to the flash hole.
TWO.........It is recommended one use magnum primer with BH209, and i don't.
I think making a deeper concavity in the breech plug will help with this issue.
When i first got this rifle i started with the crush rib sabot, because that is what i use in my Omega. They were definitely too loose. These Harvester smooth sabot are as tight as i want to deal with.
The muzzle was covered by 2 pieces of black electrical tape. There are a couple of plausible reasons for the hang fires.
ONE.......The carbon in the flash channel wasn't drilled out all the way to the flash hole.
TWO.........It is recommended one use magnum primer with BH209, and i don't.
I think making a deeper concavity in the breech plug will help with this issue.
When i first got this rifle i started with the crush rib sabot, because that is what i use in my Omega. They were definitely too loose. These Harvester smooth sabot are as tight as i want to deal with.
Have you noticed a difference in a more concave end to the BP? or have'nt you had time enough to determine this? Since BH should not draw moisture Im betting as you said the hangfire is due to the carbon in the BP.
(BP)
01-10-2010, 06:28 AM
#74
Nontypical Buck
Thread Starter
Join Date: Jan 2009
Location: Northern Chautauqua Co. N.Y.
Posts: 2,976
(BP)
01-10-2010, 09:13 AM
#75
Fork Horn
Join Date: Dec 2005
Location: My Range in Central NY
Posts: 320
Here are some photos and the numbers for my actual breech Plugs. The first photo is of both rifles, that these plugs are from. (The Modifications shown below are for my purpose and use, Proceed at your own risk)
The Remington Roller was built for use with the first generation substitutes of Black Powder. ( this category to me is all Smokeless Powder)
The Knight T-Bolt was modified to use Winchester 209 shotgun primers for the express purpose of shooting BH209. (IMHO BH209 falls in to what I refer to as the 2nd generation Black Powder substitutes.)
Here are the Rifles:
The next photo is a photo of The Breech plugs from both rifles, Notice the copper based never seize in the threads. Both rifles had been pickled for storage.
The Remington's plug is the top one. This is the Plug I made from a grade 8, 5/8 bolt along with the primer holder being from a 3/8 grade 8 bolt. The powder end of this plug duplicates the shape and dimensions of the Savage Breech plug. side view only!
The lower/longer plug is the Knight's Plug, the overall length and shape of the external portion of this plug has not been altered:
The next photo is a photo of the recessed end of both plugs with Savage style vents installed.
The Knight Plug, The right plug in the photo is recessed .325 to the face of the vent screw/liner. Notice how wet the plug is from an oily bore. WOW I even dried it with a patch before the photos
The Rollers Plug, The left plug is recessed .625 to the face of the vent screw.liner. This plug also shows that My .375 drill did not want to make a perfect smooth hole on the surface, this was a Grade 8 Bolt.
The last photo is of the primer ends of both Plugs:
Knight Plug, the Rt plug again was modified before I even started the other gun. This plug has fired in over 4 pounds of BH209 and over 400 Primers. This primer seat still shows no signs of gas cutting/erosion
This MODIFIED Knight plug's dimensions: RT Plug
from end of vent screw to top of plug: 1.082"
Primer pocket recess is a depth of : .220
Distance from inserted primer to Vent : .862 (This is the distance RonL asked for I believe )
The Roller Plug: Left Plug, this plug is shorter overall. I have fired this plug over 800 times. The Primer seat shows no sign of gas cutting erosion. The grade 8 bolt is good stuff.
from end of vent screw to top of plug: .562
Primer pocket recess is a depth of : .220
Distance from inserted primer to Vent : .340 (This demention will change due to the threaded length of vent screws.)
Both plugs are stained from experiencing Hot - Flashy situations.
Did anyone catch that I threw another situation in to the pot of thoughts. Gas Cutting of the primer seat. In 03 I bought a BPI Beartooth Magnum, I fired this gun over 1200 times as a 50 cal Muzzle Loader This was with Conical Boolits Lee REALs and my maxis. The most I got out of the Soft CVA breech plugs was 400 primers. they would develop serious gas cutting in the primer seat. Check you CVA/BPI plugs for this erosion, once it starts it gets worse fast. This rifle was shot out at somewhere less than 1200 rounds, It would no longer shot accurately. I couldn't keep it on a paper plate at 50 Yards.
This BPI Beartooth Magnum Rifle today has an extended breech plug that I made, it is 17.75" long and did require that I ream the existing barrel out from the breech end to a diamater of.562. This breech plug has a hole running it's full length and this hole has stuff called rifling in it. Instead of 209s to light the powder I use small pistol primers along with 38 special or 357 mag brass. This is my version of a Rook Rifle now.
The Remington Roller was built for use with the first generation substitutes of Black Powder. ( this category to me is all Smokeless Powder)
The Knight T-Bolt was modified to use Winchester 209 shotgun primers for the express purpose of shooting BH209. (IMHO BH209 falls in to what I refer to as the 2nd generation Black Powder substitutes.)
Here are the Rifles:
The next photo is a photo of The Breech plugs from both rifles, Notice the copper based never seize in the threads. Both rifles had been pickled for storage.
The Remington's plug is the top one. This is the Plug I made from a grade 8, 5/8 bolt along with the primer holder being from a 3/8 grade 8 bolt. The powder end of this plug duplicates the shape and dimensions of the Savage Breech plug. side view only!
The lower/longer plug is the Knight's Plug, the overall length and shape of the external portion of this plug has not been altered:
The next photo is a photo of the recessed end of both plugs with Savage style vents installed.
The Knight Plug, The right plug in the photo is recessed .325 to the face of the vent screw/liner. Notice how wet the plug is from an oily bore. WOW I even dried it with a patch before the photos
The Rollers Plug, The left plug is recessed .625 to the face of the vent screw.liner. This plug also shows that My .375 drill did not want to make a perfect smooth hole on the surface, this was a Grade 8 Bolt.
The last photo is of the primer ends of both Plugs:
Knight Plug, the Rt plug again was modified before I even started the other gun. This plug has fired in over 4 pounds of BH209 and over 400 Primers. This primer seat still shows no signs of gas cutting/erosion
This MODIFIED Knight plug's dimensions: RT Plug
from end of vent screw to top of plug: 1.082"
Primer pocket recess is a depth of : .220
Distance from inserted primer to Vent : .862 (This is the distance RonL asked for I believe )
The Roller Plug: Left Plug, this plug is shorter overall. I have fired this plug over 800 times. The Primer seat shows no sign of gas cutting erosion. The grade 8 bolt is good stuff.
from end of vent screw to top of plug: .562
Primer pocket recess is a depth of : .220
Distance from inserted primer to Vent : .340 (This demention will change due to the threaded length of vent screws.)
Both plugs are stained from experiencing Hot - Flashy situations.
Did anyone catch that I threw another situation in to the pot of thoughts. Gas Cutting of the primer seat. In 03 I bought a BPI Beartooth Magnum, I fired this gun over 1200 times as a 50 cal Muzzle Loader This was with Conical Boolits Lee REALs and my maxis. The most I got out of the Soft CVA breech plugs was 400 primers. they would develop serious gas cutting in the primer seat. Check you CVA/BPI plugs for this erosion, once it starts it gets worse fast. This rifle was shot out at somewhere less than 1200 rounds, It would no longer shot accurately. I couldn't keep it on a paper plate at 50 Yards.
This BPI Beartooth Magnum Rifle today has an extended breech plug that I made, it is 17.75" long and did require that I ream the existing barrel out from the breech end to a diamater of.562. This breech plug has a hole running it's full length and this hole has stuff called rifling in it. Instead of 209s to light the powder I use small pistol primers along with 38 special or 357 mag brass. This is my version of a Rook Rifle now.
Last edited by Screwbolts; 01-10-2010 at 09:18 AM.
01-10-2010, 05:30 PM
#78
Boone & Crockett
Join Date: Aug 2004
Location: Idaho
Posts: 11,703
Breechplug
BP I can only give you what I think I thought.... I have always thought the the flat face BP was designed for pellets - especially for Pyro pellets with the black powder accelerator on one end. And then when T7 pellets came along - I made the assumption the flat face continued to give the flash a direct path up the hole in the pellet to begin powder ignition.
The concave faced breech plug seemed like a natural for the ignition of loose powder. I offered the ability of the flash to ignite the bottom of the load -start the hot ignition and then spread. I also have to tell you that I shoot a version 2 of Doc White's 209 breech plug in my model 97. It does have a flat face and is excellent for the ignition of loose T7 as well as Pryo Pellets.
The faces of the breech plugs went through many changes with the advent of T7 and Underclocked's famous invention of the 'Crud Ring". There was an industry wide effort to change the face of the BP to help reduce the 'crud ring' build up. From that effort you can see many different designs and depth of the concave faces.
I think the next thing to follow was the 'Convex' faced BP again designed for loose powder. I think the driving force of the 'Convex' face was an effort to clean up the amount of blow back that was sent back up the 'flash hole'. The 'Convex' face would cause some of the blow back pressure to be moved away from the 'flash hole' and conversly the 'Concave" face directed the pressure into the flash hole.
The next thing that has been fooled with is the size of the 'flash hole'. I think the low end of this is .027 used by Knight to reduce blow back and to a high of .036 created by Busta to get better ignition of BH.
Just my take.... and I am not an authority...
I asked you a question about the BP and the concave end VS the Flat end and the pourpose of them, when you get a chance can you answer it on the forum?
The concave faced breech plug seemed like a natural for the ignition of loose powder. I offered the ability of the flash to ignite the bottom of the load -start the hot ignition and then spread. I also have to tell you that I shoot a version 2 of Doc White's 209 breech plug in my model 97. It does have a flat face and is excellent for the ignition of loose T7 as well as Pryo Pellets.
The faces of the breech plugs went through many changes with the advent of T7 and Underclocked's famous invention of the 'Crud Ring". There was an industry wide effort to change the face of the BP to help reduce the 'crud ring' build up. From that effort you can see many different designs and depth of the concave faces.
I think the next thing to follow was the 'Convex' faced BP again designed for loose powder. I think the driving force of the 'Convex' face was an effort to clean up the amount of blow back that was sent back up the 'flash hole'. The 'Convex' face would cause some of the blow back pressure to be moved away from the 'flash hole' and conversly the 'Concave" face directed the pressure into the flash hole.
The next thing that has been fooled with is the size of the 'flash hole'. I think the low end of this is .027 used by Knight to reduce blow back and to a high of .036 created by Busta to get better ignition of BH.
Just my take.... and I am not an authority...
01-10-2010, 06:02 PM
#79
Nontypical Buck
Thread Starter
Join Date: Jan 2009
Location: Northern Chautauqua Co. N.Y.
Posts: 2,976
Mike,
On My ACCURA's BP the end is kind of Concave and Flat...half of the outside diameter of the BP is flat the inner half of the BP is Concave. Did they make it this way to serve both pourposes of using lose powder and pellets? So if Im using lose powder a concave is better and pellets a flat end is better?
Along with drilling out my Fire Channel on My ACCURA's BP should I add more of a concave end to what's already there?
Ron (BP)
On My ACCURA's BP the end is kind of Concave and Flat...half of the outside diameter of the BP is flat the inner half of the BP is Concave. Did they make it this way to serve both pourposes of using lose powder and pellets? So if Im using lose powder a concave is better and pellets a flat end is better?
Along with drilling out my Fire Channel on My ACCURA's BP should I add more of a concave end to what's already there?
Ron (BP)
01-10-2010, 06:33 PM
#80
Boone & Crockett
Join Date: Aug 2004
Location: Idaho
Posts: 11,703
Breechplug
It would be my suggestion - do not re-work the concave end unless you are installing a vent liner. you have to assume that CVA spent some time designing the existing BP for it's best application. Opening the 'flash channel' will only increase the volume of the BP - it should not effect the flash hole or the operation of the ignition of the powder.
It would be my suggestion - do not re-work the concave end unless you are installing a vent liner. you have to assume that CVA spent some time designing the existing BP for it's best application. Opening the 'flash channel' will only increase the volume of the BP - it should not effect the flash hole or the operation of the ignition of the powder.