What is the flash hole diameter in the lehigh replacement breechplug? Also what diameter is the flame channel? The plug is for my Knight Disc Extreme 50cal. Breechplug was purchased from Knight Rifles.

Flame channel is 5/32". Flash hole seems to be 0.031" because of a coating 0.0005" thick, but in reality is 0.032". These are measurements from a nfpj plug for a disc extreme purchased from Knight.

andrewstj

Knight is still evaluating a coating process for the new BP's and vent liners that has been proposed, so at this time the breech plug and Vent liner are not treated with any coating.

A Bore Tek application is applied by Knight to the bores of the rifles only.

Ron is correct the flash channel is 5/32" and the Vent Liner specs are .031 +.001 - so it is possible to get one that is .032"

It seems to me i have purchased somewhere near 28 vent liner from Lehigh. The flash hole i measured in them were 0.032". The flash hole in the two Knight nfpj breech plug i purchased, measured. 0.031". If this difference isn't due to them being coated, my question is why the difference? Why? Why is the flash hole of the Lehigh vent liner 0.001" smaller in the Knight nfpj breech plug, than it is when Lehigh sells, and sends it to my house?

Ron read the post again... The spec for the Lehigh/Knight Vent Liner is to make the flash hole .031 and within the spec is an allowance of +.001 no minus spec is allowed. So it is entirely possible that you have vent liners with a .031 and .032 Flash Hole and both are with in specs.

Plus, I have posted in one of your threads before that they are not coated even offered the information directly from Knight that was emailed to me - they are not coated. I know you have a hard time believing a lot of things, but you could email Lehigh or Knight and ask your question directly rather supposing something that is not true.

Here is a copy of the email from Knight when I posed the question to them:

Mike,
We only apply Dyna-Tek protectant to the barrel only, internal and external. All threaded areas on the barrels are then chased with taps to assure all are correct. Please feel free to correct any nay sayers.

And just so you know all of my Vent Liners measure with my pin gages measure .031 and the .032 pin will not even come close to starting.

Even the Vent Liner with nearly 500 shots measures .031 but the .032 will almost start. But, remember I shoot primarily T7 so I can tell you what BH might do over that many shots.

The pin gages i am using are minus pin gages. Perhaps yours are plus pin gages.

When i make my vent liners using a #70 drill, the 0.028" pin gage fits, but the 0.029" pin gage will not fit the flash hole of my home made vent liner. Every Lehigh vent liner i have ever checked accepts the 0.032" pin gage. Neither of the two Knight nfpj breech plugs i purchased with the brazed vent liner would accept the 0.032" gage. To me this indicated they are coated, because i assumed them brazed in vent liner were standard Lehigh made vent liner.

In the end, i guess it doesn't really matter.

thanks guys, just wanted to make sure i had the correct drill bits for cleaning. breech plug and gun have functioned perfectly since i found the correct bullets. BH 209, CCI 209 mag primer, Thor 300gr., .502 dia.