Breach Plug project
#1
Thread Starter
Giant Nontypical
Joined: Nov 2005
Posts: 6,585
Likes: 0
Decided to see what could be done with an old flat face breech plug that came out with the early Triumph.First I purchased a Savage vent liner and measured it out it appeared to be a 10-32 thread.
I set up the breach plug on the milling table of my drill press and bored the 1/8 hole the center line to match up with the 1/8 inch hole under the primer pocket. First Pic.
Second I reamed the hole with a number 17 drill.
Third I checked the vent liner with a 10 32 thread cutter and a thread gage to be sure that's what was needed.
I got out the 10-32 tap and mounted it in the drill press chuck so it was exactly strait and in exact alignment with the hole, then I turned it by hand while I put light pressure on the tap with the drill press.
Forth I hunted through my tools and found a cutter that matched the bevel on the back of the vent liner and cut the bevel into the breach plug.
Fifth I put a bit of grease on the threads and got out a T20 screw driver head and screwed the vent liner in.
This all took about 35 minutes about next Monday if its not raining I will take it out to the range and report on how well it works. Lee

Nobody has a comment???
Last edited by lemoyne; 08-21-2009 at 12:06 PM.
#2
Boone & Crockett
Joined: Apr 2007
Posts: 10,918
Likes: 1
From: River Ridge, LA (Suburb of New Orleans)
Neat project. How big is the flash hole on the Savage vent liner? I've been wondering if it would be worthwhile to drill and tap one of my flat face Mustang plugs and use stainless socket head screws drilled with a variety of flash hole sizes just to see what happens to accuracy and blow back with different size flash holes.
#3
Thread Starter
Giant Nontypical
Joined: Nov 2005
Posts: 6,585
Likes: 0
Its just a little bigger than the ones that TC uses in there BP's. I will measure it the next time I have it out of the gun. I have been wondering about the Lehigh vent liners and if the touch hole is the same size. I was afraid that the breach plug would be hard and difficult to work with but it machined very nicely. Lee
#4
lemoyne
Just finished mine also.. I'll get some pictures up later tonight. I did mine with a lathe - it actually took longer to chuck it up than it did to do the rest of the project. I wanted to use the lathe to match the contour of the under side of the vent liner in the cavity of the BP. Then drilled it and tapped it on the lathe - everything is totally parrallel that way - came out great. The actually project after chucking took about 15 minutes. Will not have to ever buy another Omega breech plug...
Just finished mine also.. I'll get some pictures up later tonight. I did mine with a lathe - it actually took longer to chuck it up than it did to do the rest of the project. I wanted to use the lathe to match the contour of the under side of the vent liner in the cavity of the BP. Then drilled it and tapped it on the lathe - everything is totally parrallel that way - came out great. The actually project after chucking took about 15 minutes. Will not have to ever buy another Omega breech plug...
Last edited by sabotloader; 08-21-2009 at 02:44 PM.
#5
Thread Starter
Giant Nontypical
Joined: Nov 2005
Posts: 6,585
Likes: 0
Sabotloader, I thought about doing mine on the lathe, but it locked right in on the half rounds on the milling table and bored dead on. I was surprised how easy it was. I thought about opening up the 1/8 channel below the primer pocket but it could not shoot any better so I decided not to fix it. Lee
#7
Thread Starter
Giant Nontypical
Joined: Nov 2005
Posts: 6,585
Likes: 0
Grouse , Well actually we were discussing this about a year a go that's why I was saving the first Triumph BP. I was going to make one from scratch, there is actually a couple of improvements I would like to try but it seems like there is never enough time for everything.
#8
Fork Horn
Joined: Jan 2010
Posts: 414
Likes: 0
From: Ontario, Canada
Dug up this old thread searching for info to install a Savage vent liner in my Triumph breech plug. My old plug is worn. I'll purchase a new plug, but I would like to give the vent liner installation a go, on the old one.
I have ordered vent liners form PR bullets.
What I'm after is the bevel angle on the Savage vent liners, are they the same 82 degrees as the Lehighs, that I see mentioned used in other modifications?
I have ordered vent liners form PR bullets.
What I'm after is the bevel angle on the Savage vent liners, are they the same 82 degrees as the Lehighs, that I see mentioned used in other modifications?
#9
Fork Horn
Joined: Dec 2005
Posts: 320
Likes: 0
From: My Range in Central NY
Neat project. How big is the flash hole on the Savage vent liner? I've been wondering if it would be worthwhile to drill and tap one of my flat face Mustang plugs and use stainless socket head screws drilled with a variety of flash hole sizes just to see what happens to accuracy and blow back with different size flash holes.
Savage flash hole size on new Vent liners are supposed to measure .03125" . I suggest you look at cobalt drills if you plan on drilling this small a hole. A lathe is very handy for this, even a small unimat. The most certainly can be drilled with a good drill press and patience.
#10
Nontypical Buck
Joined: Aug 2008
Posts: 3,732
Likes: 0
From: Rapid City, South Dakota



