TC Encore Endeavour Breech Plug Mod

[Walkingeagle]

I have two breech plugs for my Endeavour, one still good with flashhole of 0.033” and the second shot out at 0.054”. These are the Speed Breech style plugs. A friend of mine and I got together to discuss a plan I have of installing the “Savage” style replacement liners. Did a bunch of measuring and re-measuring before setting the pilot stop for drill depth. 5/32” bit was drilled to stop depth on the drill press, from the barrel end. Hand tapped until depth was achieved via measured mark. Once everything was cleaned up, it appears it will do the job perfectly. Not sure when I’ll get the time to test it and start reworking a black powder load.
Walk

 

[michiganmuzzy]

Did you counter sink for the liner? Or are you leaving it flush at the front of the plug?

 

[Walkingeagle]

Left if flush. We both felt the existing countersink was enough that the threads on the liner that were catching are far more than enough to handle the 209 primer, while the main charge pressure is pushing towards the flush head of the liner. Also my intended use is not to extend range, but to allow me to shoot a bullet out of a .50 for close range hunting the BIG critters with 80-90gr 3f black or Pyro P.
Walk

 

[MrTom]

For black and pyro you should be good. BH209 would most probably require a counter-sink job. Not certain on T-7 but I never had an issue with a conventional factory plug, which is what you basically have, and the granular T7.