Gm54-120
I get different results with the Gen I in 3 different Disc based rifles. The Gen I works great in the GMB54, its ok (needs improvement) in the Extreme 50 and pretty dirty in the Eilte 45. Although ignition is very good in all of them i really like it in the Elite 45 in terms of ignition.
That is exactly the problem... Knight tolerances - not that they are out of line industriall, because they are not they work for them and helps keep the costs down, especially when you are competing in a very competitive market.
But, because of the margin of tolerances, it is difficult to be build a universally clean plug for all bolt action Knights. Lehigh has changed their application statement to reflect these tolerance differences. From all the information collected it appears that the Generation II plug should work very well in most of the Knight DISC Elite and Extreme models manufactured after the "Original' DISC. Other models built and offering the Extreme bolt it may be a toss-up. The Knight DISC original even with the Extreme bolt conversion does have a significant difference in the depth of the breech plug compartment in the barreled action. This difference does not allow the plug to achieve the proper primer depth in the Lehigh BP. Scott, and on the other end it appears that the GM54-120 has more shallow breech plug depth so you are are able to insert the primer deeper into the plug and get a better blow back seal. I have a Knight DISC MHC and the Lehigh works very well in it. So I am thinking it will work in most MHC's but I am not sure about the initial Master Hunter - but probably????
Another bit of history... in the new Lehigh Generation II plug the primer pocket depth has been set at 0.195" the Generation I plug was set at 0.245". For my 5 now 4 Knight DISC's this is really 0.005" of an inch longer that it needs to be, but to cover 90% of the Knights out there this measurement should work and work well. In my tightest gun, a combination of bolt length and breech plug pocket depth in the barrel, I need a primer pocket depth of 0.188" for that gun to be 99% blow back free. Two others take a 0.190" and the last needs a .0192" primer pocket. The 0.195" number should allow everyone nearly 85/90% blow back free operation.
Do not know if the Lehigh would agree with that, but that is what I think...
I know one thing.... it is a ton easier to clean up the gun after shooting with a Gen II plug... Cayugad would argue that it really does not matter because cleaning a ML is a "labor of love" - from there 'no comment'
mike