Breech Plug - Vent Liner Project

[sabotloader]

Well since I retired again! and I am suppose to have more time - I tackled my next project... installing a Savage type vent liner in a Breech Plug - preferrably a BP that has been burned out. I got a selection of vent liners from Grouse last week.

Problem... I do not have any burned out BP's like that so I took a brand new Omega BP to a friends Machine Shop - explained to him my problem and my thoughts and he said lets go do it.

I thought he would take it to a drill press and complete the work, but he chose to put it on a lathe as he wanted every thing to be parrallel and he wanted to match the contour of the bottom of the Vent liner with a simular detent in the bottom of the breech plug.

After he took his measurements and got the information he needed he chucked the BP and went to work. It actually took him longer to chuck up the BP than it did to create the VL pocket in the BP, drill out the flash channel, then run a 10/32 tap in the new flash channel. He estimated the next one would take him 15 minutes - start to finish. I am still sure you could do almost as well on a good drill press - think Lee proved that.

The flash hole in the 'Domed' Lehigh liner is .032 and the one in the flat Savage is very very close to the same. I am actually thinking the domed liner might provide less blow back.

Now, if the weather would cool down I would run out to the farm and give it a try. Might be a few days. But I am convinced this is the way to salvage BP's - buying vent liners is a lot cheaper than buying BP's.

If this works as well as I think it might grab a new Knight plug and do the same thing...

Here are some pictures of the project...



Hope this helps explain the project....

[jims]

Nice work.

[grouse]

This is a easy fix for worn out breech plugs. Especially the speed breech plugs from T/C. $34.95 at my local shop. And also the plugs that are having problems igniting BH209.

Did you drill the flame channel the whole way through the plug? I think that is a must and will now guarantee BH209 ignition with most plugs when that is done.

Nice job and thanks for the report. I have a couple worn out plugs i might just try this with.

[sabotloader]

It is drilled and tapped all the way through, the same as a Rem 700ml Breech Plug.

I am really thinking that Spitpatch is correct in his assesment of the Vision BP having the larger 'flash channel' allows more room for expansion and therefore less blowback out.

It is drilled and tapped all the way through, the same as a Rem 700ml Breech Plug.

I am really thinking that Spitpatch is correct in his assesment of the Vision BP having the larger 'flash channel' allows more room for expansion and therefore less blowback out.



This is an interesting assesment from another forum about the project...


Quote:
I think in a rifle like an Omega the domed area around the flash hole would be the way to go. If you have ever looked into the mechanics of an explosion for demolition purposes you evidently understand the ideas behind focused explosive pressures. What your saying goes right along with all those thoughts.

[lemoyne9]

Sabot loader
Do you think that it would improve the blow back control if the hole back to the primer pocket were drilled larger than the #17 drill I used for the right size hole to tap the 10-32 threads in?Lee

[grouse]

Sabotloader,
The Vision plug is different from the Elite/Extreme plug. The reason i think it gets less blow back is the primer is up against the plug. The Elite primer isnt up against like you pointed out. i cant wait to see what Dave comes up with.

[sabotloader]

Lee

In my nomenclature - the 'flash channel' is the channel directly under the 209 primer that carries the flash and pressure to the 'flash hole'.

It is my belief that if you can increase the volume of the flash channel you can reduce the amount of blow back that you might see in the breech. Ideally if you flash channel would hold all of the blow back pressure from the flash hole until the bullet exits the bore you would have 0 blowback becasue as soon as the bullet leaves the bore it will create reverse pressure situation and suck out the pressure.

So if any of this makes any sense then I think increase the volume of the flash channel either by making it longer as they did in the Triumph or making it large in diameter will accomplish what i think I am talking about.

Tom is correct about the Vison plug, but the shelf that primer sits against does not seal it after the shot as the primer is push back against the receiver a small amount and off the shelf - but the diameter of the flash channel is greater in that plug than any of the elite/extreme breech plugs. Enough so, I think, to reverse the whole blow back situation and again the Triump does it with its longer flash channel.

Just my thoughts...

[bigiron]

I'm new to the site(today)and have been doing alot of reading on here. I've been shooting ML's and CF rifles for a long time.Currently shooting a Omega.This vent liner thing is new to me.Can you explain it abit more to me? My Omega dose not have anything like this,should it have one,or are these for smokeless?

[sabotloader]

bigiron

The vent liner project is a method I have tackled to extend the life of a burned out BP.

At some point your flash hole will become gas cut or enlarged, causing some loss of accuracy. Most would just replace the BP at what ever cost that might be. For me installing a $4 vent liner in the old BP is cheaper and from there I can just replace the ventliner as needed.

You can see I took my Omega plug drilled and tapped it to install the liner.

Hope this information helps....