Jason since BH is a smokeless progressive burning powder, it does not function as real BP or other BP subs do. And BH is a BP sub otherwise they could not get it approved for use in a lot of states.

BH is a nitrocellouse based powder and because of that it's ignition temperature is much higher than reall BP or any of the other subs.

Because of this elevated ignition temperature a hotter ignition source needs to be used. Using the hotter ignition primers and combined with the much higher temps that BH works at, it does create additional stress on the breech plug. There are couple of ways to help allieviated the stress on the breech plug. One is to make the breech plug burn and pass the gasses and debris from the primer out of the breech plug as quickly as possible and the second part of the equation is to keep as much of the hotter gases in the bore from returning back through the breech plug. A third part of the equation is the timing that it takes to get the bullet out the bore. If you have room to store a greater volume of gas in the flash channel and/or deflect some of these gases back into the bore - you do lessen the stress on the BP and the flash hole.

This is all something that a few of us learned a long time ago. Tom asked why? along time ago and them with information gained from his use of a Savage he began the developement of what we/he calls a BH compatible plug. Busta about the same time was redesigning breech plugs for the NEF. Then for me the real key came when Gordy Edwards redesigned the breech plug for the Vision ML and it became so successful.

So using that information, information from Tom and comparing thoughts with Busta the light started to come on.

I shared my thoughts a couple of times on the net and then one day Lemoyne decided to take some of the information and rebuild a shot out Omega plug then a Triumph plug. They functioned very well for him and then the race was on...

Lehigh built a Generation I conversion for Knight DISC rifles, that conversion allowed to much blow back into the breech area. It worked great shooting BH, but was not as clean as Tom or might have wanted. We redesigned that one and came out with a Gen II plug that works very well. I actually asked Dave to build a Generation III plug with the vent liner on the end of the plug increasing the length and volume of the flash channel. I shoot the Gen III in 3 different Knights and it works great, reduces the blow back pressure on the nose of the primer and ignites BH with the coolest 209 I can find.

It just plain works.