Encore 209 breech plug blow back.

[Oldranger]

Shooting a moderate load, 70 gn by weight of BH 209. 285 gn PB.
The Winchester primers are totally flattened and the rims are all ruffled up.
There is black residue around the outside of the barrel. The barrel has a tight fit. I havnt modified the breech plug. The flame hole is very small.
I havnt noticed this with other powders and stiffer loads. Do I need a different breech plug for Blackhorn powder or a different primer ?

 

[MrTom]

Oldranger, I'd measure the size of the small hole in the breech plug. It may seem "small" to look at, but actually be too large and you could be getting too much back pressure through it. Without measuring it you can't know for certain.

If the plus is indeed shot out find someone to convert it to vent liner use instead of tossing it. Replacing a liner every couple hundred shots costs maybe $6.00 instead of the cost of a new plug.

 

[ElDiablo]

Great advice. I agree. Measure the flash hole. I don’t recall what a factory plug starts at. Maybe .030 or so? If the flash hole isn’t eroded beyond .036” I’d try a McMaster-Carr o-ring.

And, I assume you’re cleaning out the carbon from the flame channel with a drill bit? Is this an ancient plug (flat faced), the newer (concave) style or a Speed breech plug?

 

[Oldranger]

Great advice. I agree. Measure the flash hole. I don’t recall what a factory plug starts at. Maybe .030 or so? If the flash hole isn’t eroded beyond .036” I’d try a McMaster-Carr o-ring.

And, I assume you’re cleaning out the carbon from the flame channel with a drill bit? Is this an ancient plug (flat faced), the newer (concave) style or a Speed breech plug?

Drill out the flame channel ? I don't understand. Is the flame channel the hole thru the breech plug ? if so, that's a tiny bit. I can only get a small sewing needle thru my breech plug. It is concave. As a longtime reloader, I'm concerned about the over pressure signs on my primers.

 

[gle3105]

My guess is the flame channel ( not the small flash hole ) is carbon clogged.
The larger hole where the primer empties it’s charge into the breech plug.
Use torch tip cleaners for the small hole.
Start with a bit slightly larger than the flame channel carbon clogged opening. Then increase in size until you get close to metal.
OEM’s usually have bit sizes in their owners manual about breech plugs.
Shown is a new FX bp. That’s a .127 pin gauge in the flame channel. So a 1/8” is close.
The other is the torch tip cleaner.

 

[ElDiablo]

Carbon builds up in the flame channel in front of the primer and has to be reamed out with a drill bit.

 

[Oldranger]

Got it. thanks

 

[ElDiablo]

If the face of the plug is concave it sounds like the newer style that is compatible with BH209. So as @gle3105 says, clean it out and then check the size of the flash hole using torch tip cleaners. Let us know how it works out.

 

[Oldranger]

Did some measuring. From the breech end a 0.043 pin goes almost all the way thru. From the muzzle end a 0.036 pin will not enter.

 

[Oldranger]

 

[Oldranger]

This drawing is not of my plug. There really is no long flash channel. The primer sits against the hole and sits halfway out of the channel

 

[WV Hunter]

The flash hole isn't typically a concern, its the buildup in the sidewalls of the flash channel that creates problems. It chokes the space closed. BH209 gets hard like concrete and should be cleaned out after every range session. Hand drill it out. I don't know what size bit that BP takes, maybe 1/8"? Someone can chime in to verify that I'm sure.

 

[ElDiablo]

Your plug looks like this right? How many rounds through that plug? I’m betting you’ve got serious carbon build up if you’ve never drilled it out.

 

[jlink]

My encore has always as blowback to the point where the old silver TC scope had a defined stain on if from blowback. Always shot Winchester 209s in it but never noticed deformed primers

 

[bronko220002]

My guess is the flame channel ( not the small flash hole ) is carbon clogged.
The larger hole where the primer empties it’s charge into the breech plug.
Use torch tip cleaners for the small hole.
Start with a bit slightly larger than the flame channel carbon clogged opening. Then increase in size until you get close to metal.
OEM’s usually have bit sizes in their owners manual about breech plugs.
Shown is a new FX bp. That’s a .127 pin gauge in the flame channel. So a 1/8” is close.
The other is the torch tip cleaner.

Carbon builds up in the flame channel in front of the primer and has to be reamed out with a drill bit.

View attachment 29055

Did some measuring. From the breech end a 0.043 pin goes almost all the way thru. From the muzzle end a 0.036 pin will not enter.

Do what the other guys suggests and as for the flash hole it should be no larger than .035". With your pin gauges you should be able to insert a .034" pin as the biggest. (Note: you can't put a .035" pin in a .035" hole) You said you can't put in a .036". Did you try .035"? If that will go in then you're right on the edge of your BP's life.
Clean out that BP as mentioned and let us know how it works.

 

[Oldranger]

I clean both ends of the BP after every session. I see shiny metal in there.
The hole is messed up. I found a new BP. Also, I found some wobble in the barrel. Replaced the """" custom """ hinge pin with the original which is a pita to insert, but no more wobble. Headed to the range.

 

[scratcherky]

My encore has always as blowback to the point where the old silver TC scope had a defined stain on if from blowback. Always shot Winchester 209s in it but never noticed deformed primers

I use a rubber oring in my plug under the primer and it completely eliminated the blow back.