The plug in my Triumph has the concavity on the end just like the Omega plug, and just like the home made Accura plug. My Triumph plug, with this 'powder pocket', has been 100% reliable with BH. It has a flash hole of 0.028", as does the Omega plug, as does the home made plug. The Triumph plug has a flash channel of 1/8", as does the Omega, and the home made Accura plug.

These plugs have several things in common, and they are all 3, 100% reliable with BH.

If i understand correctly, you feel the Triumph plug needs modifying. Myself, i haven't found this to be the case. The Triumph plug, and the Omega plug work great using BH, just as they come from TC.

I am puzzled why You and some other on these forum, insist that a plug needs a 5/32" flash channel, and a 0.032" flash hole to be able to work successfully with BH. This just simply isn't true.

Myself, i have experienced great success with breech plug that have a 0.028" flash hole, and a 1/8" flash channel. You, and some other want to believe the commonality of successful plug is not the concavity of the end of the breech plug, whereas i see this 'powder pocket' as being the single common thing of all successful BH breech plug. My experience is, of course, limited, but all the successful BH breech plug in my life, have either a 3mm or 1/8" flash channel, and anywhere from a 0.028" to a 0.32" flash hole. The singular thing all these successful plug have in common is the 'powder pocket'. It also has been written that the reason some plug work well with BH is because the concavity in the end brings the powder closer to the primer, and that this is why they are good plugs. It seems to me, the Triumph plug shows this explanation is false. Another plug that has the powder quite far away from the primer, is the QRBP with a vent liner installed. Mine has been 100% reliable using BH in single digit temperatures. I have only shot it about 50 times, so i am not able to make a very strong case for it's success as of yet.

To answer your question as to whether i have played around with the TC speed breech; the answer is no i haven't, and the reason why is, because it works perfectly just the way TC sent it to me.

I assure you, i have no agenda or belief to push, rather, i just want to shoot my rifles without wondering if they will go boom.