.45-70 Begara conversion, need breech plug

[mnoland30]

I got a great deal on a .45-70 Begara 209 conversion on eBay, but I'm having trouble getting it to shoot well. I'm thinking it could be that the breech plug is worn out, and even if it isn't, I know I'll need one sometime. I have no idea who did the conversion or what plug they used. Mine measures .683 inches on the threads, and is 28 threads per inch. I'd welcome some feedback on what this could be. Also, I'd be interested in what the proper diameter hole is, and what size is too big.

 

[Busta]

Can you post a picture of the breech plug?

 

[GM54-120]

There were at least 3 guys that did Apex and T/C 45/70 conversions. All 3 used different plugs. Without pics or more info its nothing but a wild guess.

Flash HOLE over .036 needs replacement whether its a bushing or a vent liner.

 

[derfhunter]

28 threads per inch is very fine thread, the savage plug is .683 on the threads but only a 16 or 18 thread per inch

 

[mnoland30]

You're right, I must not have had my glasses on. It is 20 threads/inch. This is for my Encore rifle.

I'll attempt to post photos.

 

[derfhunter]

I have not seen that plug so I can not help you

 

[GM54-120]

That looks like a old style Omega plug with a vent liner added. Im not aware of anyone that used those for SML conversions.

 

[Busta]

Old Encore breech plug with a vent liner.

Looks like a ShadeTree gunsmithing job to me. If it's headspace properly, I would remove the vent liner, check the flash hole diameter, and use a 5/32" drill bit to cut the carbon out of the flame channel. .

Replace the vent liner with a new one if over 0.035".

It appears that you have excessive headspace by looking at the carbon on the walls and shelf of the primer pocket. It also appears that the shoulder in the barrel or the face of the plug might not have been cut as square as it could have been.

An o-ring or shim in the bottom of the primer pocket might help get you a better seal on your primer.

Take just a bare primer with no load in the rifle. Measure the length before firing, then measure the length after firing, and this will give you your exact excessive headspace. Adjust accordingly to give you ~ 0.003" of interference (crush) in your primer of choice.

 

[ronlaughlin]

Assuming you are trying to accurately burn Blackhorn powder; not smokeless. Me, i would not use that plug for smokeless. Assuming you are trying to accurately burn Blackhorn powder, believe it would work better if the vent liner is set deeper into the plug e.g. photo

The pictured plug reliably ignites Blackhorn in my Omega, and the bullets fly straight. Next photo show the o-ring in place to insure a good seal for loose head space.

 

[Chick]

What is the picture of the gas burner, for?

 

[SuperKirby]

That appears to be an Omega/Encore plug as previously stated. I had one done a few years ago by CMC (Cole) from Dougs Message Board. Mine had a bushing added instead of a vent liner and I was told it was safe for smokeless. I only put maybe 100 shots through it but it worked fine. I am NOT telling you your plug is safe for smokeless and wouldn't tell anyone to shoot smokeless out of it. Were it me, I'd buy a new Encore/Omega breech plug and use it as a BH209 barrel.

 

[mnoland30]

Thanks for all of the advice. I tried an o-ring in front of the breechplug, but the gun wouldn't close. I'll see if I can find one to fit in front of the primer. I can't use smokeless here in NM for hunting, so I'm not trying for that. I use 777 and BlackMZ, Blackhorn is just too expensive at 4 times what I pay for BlackMZ. I've tried it, and couldn't see that it was worth the cost. I measured the flash hole, and it is just under .035. Does anyone have an Omega/Encore plug that can confirm the measurements? The gas burner appeared by magic, and I couldn't seem to get rid of it.

 

[ronlaughlin]

The flash hole in a new Omega/Encore plug will measure about 0.029".

 

[GM54-120]

Lets see. you say you cant get it to shoot well.

What loads have you tried including the sabot you used?

 

[mnoland30]

I'm hoping to use a heavy bullet without a sabot, that is why I'm using a 1:20 twist. I've tried 90 and 100 gr. of 777 and BlackMZ under a 460 gr. No Excuses and a 425 gr. GT bullet. I get 3" 3 shot groups, and then a couple of flyers that take the group over 6" at 100 yds. This is a new barrel for me, and I'm still trying to find a bullet that fits correctly. The .451 No Excuses go in too easily. I've knurled some Harvester Scorpion PT bullets to fit, but won't shoot them until tomorrow. Do you recommend weighing your charges? I tried it once with 777 in my 50 cal. and couldn't tell any difference in group size.

 

[GM54-120]

I would wager your Apex bore is near .451 on the lands. So you want a .452-.453 bullet OD if its lead. Jacketed is another ball game and requires much more accurate sizing.

Get some .462x.060 Walters wads. They are a veggie wad. Also get some wool wads. Even 50cal wool wads if you cant find them in 45cal. Some guns prefer veggie and some prefer wool so try both.

IMO 90gr is gunna be near the upper end with Triple7 and lead conicals. Less might give you better results. I would try less before i tried more.

Never had much luck with BlackMZ. The grain size is all over the place so weighing may help.

 

[mnoland30]

I talked to Badgerridge.com, and determined that the vent liner is probably the same as a Savage. I tried the knurled PT Scorpions, with poor results. I also tried some .358 bullets in a MMP sabot, and they grouped 3 shots in 3" at 50 yards, but not at 100.

 

[sabotloader]

I talked to Badgerridge.com, and determined that the vent liner is probably the same as a Savage. I tried the knurled PT Scorpions, with poor results. I also tried some .358 bullets in a MMP sabot, and they grouped 3 shots in 3" at 50 yards, but not at 100.

I do not know if this will provide any additional information at all but I will post this set of pictures.

I like may others have modified the Omega style breech plug for the insertion of Savage type vent liner. The Omega style breech plug was picked by Western Powders as their #1 favorite type of BP for the ignition of BH. The Flash Holes in these two vent liners measure 0.031" new.

I have never had an interest in shooting smokeless and so I am not aware of what properties are necessary for a smokeless breech plug.

Again all this may be irrelevant to this conversation....

 

[mnoland30]

I was looking at old posts today, and realized I never updated this one. Thanks to all of you who helped me figure this out. Badger Ridge sent me some Savage vent liners and they worked. I lowered my load down to 80 grains of Black MZ and shot some home cast 405 gr. bullets, and got a cloverleaf.