One Simple; One Technical
01-31-2017, 11:45 AM
#1
Nontypical Buck
Thread Starter
Join Date: Aug 2008
Location: Rapid City, South Dakota
Posts: 3,732
One Simple; One Technical
In the days, weeks, and months to come, i figure on shooting hundreds, and hundreds of shots. Hopefully some good will come from this practice. Hopefully my off hand shooting will improve. Follows is a couple of things i have done to a breech plug to help it last, and to help the shooting go better through the Spring, Summer, and Fall.
The simple breech plug modification.
The photo shows one way to enlarge the flame channel of the breech plug to 5/32". Install a 5/32" drill in the motor, grab the plug, and have at it. The factory 1/8" or 3mm flame channel guides the drill. One can feel when the drill hits the flash hole. When the drill hits the flash hole; quit.
Why, why do this? When warmer weather arrives my primers start to leak between the cup, and the anvil. Theoretically, the larger diameter flame channel with it's larger volume will absorb some of the excess pressure.
The technical breech plug modification.
After centering the breech plug, a 0.244" end mill, was used to make the primer socket 0.019" deeper. This allows one to utilize a metric o-ring under the primer. Why do this? It completely stops blow by around the nose of the primer; the primer seat will never get flame cut.
After a couple hundred more shots through this breech plug, the flash hole will grow so it allows too much pressure to the primer. Then the last modification will be done; a vent liner will be installed.
..
The simple breech plug modification.
The photo shows one way to enlarge the flame channel of the breech plug to 5/32". Install a 5/32" drill in the motor, grab the plug, and have at it. The factory 1/8" or 3mm flame channel guides the drill. One can feel when the drill hits the flash hole. When the drill hits the flash hole; quit.
Why, why do this? When warmer weather arrives my primers start to leak between the cup, and the anvil. Theoretically, the larger diameter flame channel with it's larger volume will absorb some of the excess pressure.
The technical breech plug modification.
After centering the breech plug, a 0.244" end mill, was used to make the primer socket 0.019" deeper. This allows one to utilize a metric o-ring under the primer. Why do this? It completely stops blow by around the nose of the primer; the primer seat will never get flame cut.
After a couple hundred more shots through this breech plug, the flash hole will grow so it allows too much pressure to the primer. Then the last modification will be done; a vent liner will be installed.
..
05-09-2017, 12:17 PM
#4
Nontypical Buck
Thread Starter
Join Date: Aug 2008
Location: Rapid City, South Dakota
Posts: 3,732
Update
This breech plug now has seen several hundred shots. It has been used in seven different Omega rifles. The oldest has a serial # 40,XXX. The newest TC serial # is 155XXX. The newest Dream Season has a Smith Wesson mark. The plug works good in each, and every Omega. No primers stick. No primers leak. No blow by. Ignition is perfect.
The photo shows the STS primers popped yesterday, and the W209 primers from this morning.
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P.S. Imagine using the same one breech plug in seven different Knight rifles.
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The photo shows the STS primers popped yesterday, and the W209 primers from this morning.
_______________
P.S. Imagine using the same one breech plug in seven different Knight rifles.
___________________
05-09-2017, 12:47 PM
#5
Boone & Crockett
Join Date: Jan 2004
Location: Eastern PA
Posts: 12,746
Ron that sounds easy enough. And the second as long as one has access to a drill press shouldn't be that hard either. Just one question. What size O-rings are you using and where do you get them? (I guess that's 2 questions)
I have the original BP from my Accura that is just sitting in my parts bin and I'd like to try that.
I have the original BP from my Accura that is just sitting in my parts bin and I'd like to try that.
05-09-2017, 01:19 PM
#6
Nontypical Buck
Thread Starter
Join Date: Aug 2008
Location: Rapid City, South Dakota
Posts: 3,732
Well i believe the o-ring i have been using is the highlighted item. The CVA rifles i have shot came from the factory with a head space loose enough the o-ring can be used without modification; no need to make the primer socket deeper.
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05-12-2017, 04:34 PM
#9
Nontypical Buck
Join Date: Feb 2003
Location: Virginia / West Virginia
Posts: 4,906
Ron have you ever modified an Omega BP to install a vent liner in it?
For someone like me, probably not needed - it would take me a long time to wear one out. Someone who shoots a ton...maybe?
For someone like me, probably not needed - it would take me a long time to wear one out. Someone who shoots a ton...maybe?
05-12-2017, 05:46 PM
#10
Nontypical Buck
Thread Starter
Join Date: Aug 2008
Location: Rapid City, South Dakota
Posts: 3,732
Sure, it is trivially easy to do, but i don't like to do it. Doing so shortens the already short flame channel, which reduces the volume of the flame channel, which reduces the ability of the channel to absorb pressure. This plug is doing fine; the flash hole hasn't enlarged much, even after several hundred shots. The reduced load of 60 (weighed) grain i have been shooting, seems to be easy on the flash hole, and even now with warming weather, the primers show no sign of excess pressure.
The day will come i guess, where the flash hole will be too large to hold back pressure, or will leak powder. Then i will have to decide to install a vent liner, or switch to a new plug.
Another option would be to use the PR adapters, and large rifle magnum primers. The rifle primers don't erode flash holes no matter if the powder charge is excessive. Theoretically, the breech plug may last forever, if the primer seat doesn't flame cut.
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The day will come i guess, where the flash hole will be too large to hold back pressure, or will leak powder. Then i will have to decide to install a vent liner, or switch to a new plug.
Another option would be to use the PR adapters, and large rifle magnum primers. The rifle primers don't erode flash holes no matter if the powder charge is excessive. Theoretically, the breech plug may last forever, if the primer seat doesn't flame cut.
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